GEOLOGICAL ILLUSTRATIONS, (2)

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BY

PROFESSOR JAMESON.


In Civil History records are consulted, medals examined, and antique inscriptions deciphered, in order to determine the epochs of human revolutions, and verify moral events; so in Natural History we must search the archives of the world; draw from the bowels of the earth the monuments of former times; collect the fragments, and gather into one body of proofs all the indices of physical changes, which may enable us to retrace the different ages of nature. It is thus only that we can fix some points in the immensity of space, and mark the progressive stages in the eternal march of time.


ILLUSTRATIONS.

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Note A and B, p. 9.

On the Subsidence of Strata.

M. Cuvier adopts the opinion of De Luc, that all the older strata of which the crust of the earth is composed, were originally in an horizontal situation, and have been raised into their present highly-inclined position, by subsidences that have taken place over the whole surface of the earth.

It cannot be doubted, that subsidences, to a considerable extent, have taken place; yet we are not of opinion that these have been so general as maintained by these geologists. We are rather inclined to believe, that the present inclined position of strata is in general their original one;—an opinion which is countenanced by the known mode of connection of strata, the phenomena of veins, particularly contemporaneous veins, the crystalline nature of every species of older rock, and the great regularity in the direction of strata throughout the globe.

The transition and floetz-rocks also are much more of a chemical or crystalline nature than has been generally imagined. Even sandstone, one of the most abundant of the floetz-rocks, occasionally occurs in masses, many yards in extent, which individually have a tabular or stratified structure; but, when viewed on the great scale, appear to be great massive distinct concretions. These massive concretions, with their subordinate tabular structures, if not carefully investigated, are apt to bewilder the mineralogist, and to force him to have recourse to a general system of subsidence or elevation of the strata, in order to explain the phenomena they exhibit.

Note C, p. 13.

Deluge.

There are many facts, some of which are recorded in the Bible, that are hostile to Cuvier and De Luc’s opinions stated in the text, viz. that the bed of the ocean was changed at the flood, or last great catastrophe; and that the land, formerly occupied by animals, was henceforth given up to fishes and other marine tribes. We are told, for example, that the dove, which was sent forth from the ark, found an olive-tree, whence it plucked a leaf, to carry back to the patriarch, as a proof that the waters of the deluge were subsiding; and we also find that the Assyrian rivers, which originally marked the situation of Eden, retained the same geographical relations after the earth had been repeopled. The natural history of the fossil organic remains contained in alluvial deposits, is also in opposition to the opinion of De Luc.

Note D, p. 19.

FORMATION OF PRIMITIVE MOUNTAINS.

Mitscherlich, in a memoir read before the Royal Academy of Berlin, but not yet published, enters fully into the illustration of the igneous origin of mountains, especially those of the primitive class, deducible from his experiments on the formation of minerals by fusion. As the view is interesting, we shall here give a short sketch of it.

Have the primitive mountains of our globe, whose form necessarily supposes a fluid state, been dissolved in water; or has the temperature of our earth been raised to such a degree, that the substances of which our primitive mountains are formed have become fluid? This question has been differently answered, and the solutions given have been attempted to be supported in proportion as the observation of geological facts, and the inquiries instituted with reference to the chemical combinations which compose the earth, have been developed. New observations, and the discovery of unknown laws in chemistry and mineralogy, must, at the same time, open a new field for speculation and observation in geology. Of the discoveries of our own times, there certainly is none which has exercised a greater influence upon mineralogy than that of determinate proportions, and especially the result of the researches of Berzelius, that the chemical combinations which nature produces, are formed according to the laws which he has discovered with regard to artificial combinations; a result which has entirely changed the aspect of this science, and has elicited a new system of mineralogy, in which the natural-chemical combinations are ranked with those which are artificial; which affords a confirmation to the laws of crystallography, as being the same in both cases.

It has been objected to the truth of the position, that the laws of natural combinations are the same as those which artificial combinations follow; that chemistry can decompose minerals; but that, in the formation of these combinations, natural laws have been in activity, which art would in vain attempt to reproduce: but this objection is groundless. The chemical affinity which acts in artificial combinations is a power of nature, as well as the affinity which regulates the composition of natural combinations: chemical affinity, in general, is a quality of matter. In this objection, modifying circumstances have been confounded with laws. The chemist would very easily refute the objection, if he could compose minerals of their elements, and produce artificial combinations similar in all their characters to minerals themselves. From such researches, there would, at the same time, be diffused a new light upon geological investigations. In this manner many phenomena would be reproduced, which have taken place at the formation of the earth; geological observations would be repeated by experiments, which might be varied at pleasure, for confirming these observations; and the recurrence in nature itself would be sought of those phenomena which have been produced in the laboratory;—inquiries, which are, however, of great importance, because they may be arbitrarily disposed and arranged according to the theory in view.

The importance of such attempts shew the value of any experiments that go to prove the formation of minerals by artificial means; and Mitscherlich has been very successful in detecting several mineral species formed artificially.

Berzelius has shown, in his Chemical System of Mineralogy, that the greater part of the chemical combinations of which our Earth is composed, and especially the primitive mountains, are analogous to salts and double salts; and that, in these combinations, the silica, carbonic acid, and oxide of iron, act the part of acids; the silica combines with the alumina, lime, magnesia, protoxide and peroxide of iron, protoxide of manganese, potash and soda, forming, with these bases, either simple salts, or double salts, in proportions determined by the different degrees of saturation; the carbonic acid is combined with the lime and manganese, and the peroxide of iron with the protoxide.

The object which should be proposed in these attempts, of which we speak, is to investigate the relation of these bases to the three acids. We find ourselves fortunately seconded in this attempt by a branch of national industry; for the complete extraction of the greater number of metals depends upon the relation of the silica to the above-mentioned bases, the degrees of saturation in which the silica may occur with them, the greater or less degree of affinity with which these bases combine with the silica, and, lastly, the chemical qualities of the combination formed. It is necessary for the metallurgist that he endeavour, in order to attain his object completely, to produce, in proportion as the minerals differ, different chemical combinations of the substances which compose these minerals; but always in determinate proportions, either by adding a foreign substance, or by regulating the fusion by the choice of minerals. The combinations which the metallurgist thus produces, are ordinarily minerals which have already been found in nature, sometimes even new species.

During a journey in Sweden, Mitscherlich observed at Fahlun, where he made inquiries regarding the ores, the scoriÆ, and in general regarding the extraction of copper, in order to form a correct idea of this operation, not only some well-formed crystals in the scoriÆ; but also found that the whole mass of the slag had a crystalline texture; and that the crystals, and the joints of the slags which had a lamellar texture, remained the same at different periods of fusion, provided only that the manner of operating of the metallurgist remained the same. The examination of the crystalline figure of the slag proved, that it was that of a mineral which has a composition analogous to that of the slag. After having made this observation, he found in almost every foundery which he visited in Sweden, different crystalline combinations, which resembled minerals. Thus he found at Fahlun, silicate and bisilicate of protoxide of iron; at Garpenberg, mica, and several times augite and chrysolite. These combinations have not only the same crystalline figures, but also all the other characters of the corresponding minerals.

I have pursued these inquiries, says Mitscherlich, since my return from Sweden; I have analysed the productions which I have found, and the analysis has confirmed what the exterior had led to anticipate. I have also augmented my observations by journeys in various districts of Germany; and farther, I have been seconded in my researches by my friends; so that I now possess upwards of forty different species of crystallized chemical combinations produced by fusion, the greater number of which are minerals already known; some are new species, which have not hitherto been met with in nature.

The occurrence of mica, which forms a predominant constituent part of our primitive mountains, as an artificial production, gave rise to the following geological speculations.

The artificial production by fusion, of the minerals which compose our primitive rocks, appears, according to Mitscherlich, to place beyond doubt the theory that our primitive mountains were formerly a melted mass. Such a state of fluidity, he continues, affords an easy explanation of the figure of the Earth, of the increase of temperature as we proceed into its interior, of hot springs, and of many other phenomena. With respect to this theory, we may refer to M. Laplace, who is convinced of its plausibility, without grounding his belief upon the reasons which chemistry presents. I propose, however, to make mention of a few facts, in order to shew with what facility many chemical phenomena in geology may be explained by following this theory.

Primitive mountains are generally distributed over the surface of the earth: it necessarily follows that the bodies which have composed the surface of the earth have participated of the temperature which the primitive mountains have had at the period when they were in a fluid state. The temperature at which water boils depends upon the pressure of the atmosphere; and if the temperature of the earth increases, we only require to diminish the mean height of the sea 32 feet, in order to have a pressure of an atmosphere more; and it is by this pressure that the degree of temperature at which water boils will also be raised higher. M. Laplace judges from the height of the sea during flowing and ebbing, that the mean depth of the sea is about 96,000 feet. Supposing three-fourths of this mass of water were converted into vapour, the pressure of this vapour would be nearly equal to 2250 atmospheres; and this pressure would so augment the degree of heat at which water enters into ebullition, that the primitive mountains might be in a state of fusion, without the water with which they are covered being heated to the boiling point; for the water which is not converted into vapour, and whose quantity is a fourth of the whole mass of vapour, according to the supposition which we have made, would cover the whole earth, because water expands in increasing proportion if the temperature be raised, and because the expansion of water is much greater than that of the mass of our primitive mountains; and, consequently, according to this supposition, our primitive mountains are formed, covered with red hot water. The great pressure of so many atmospheres necessarily modifies the reciprocal affinities of the substances which compose the primitive mountains.

Primitive mountains are distinguished from volcanic productions in this, that the lime and magnesia, which in them are combined with carbonic acid, form with the silex silicates and bisilicates. It is necessary that the silex, which, under the ordinary pressure, and at an elevated temperature, expels the carbonic acid, exercise no influence under the pressure of so many atmospheres; and it is not surprising that crystals of quartz occur in Carrara marble. In volcanic productions, this pressure no longer exists, and we should find among these the same phenomena which our laboratories and metallurgic operations present. Following this theory, the circumstances that primitive mountains contain gypsum and carbonates, and that water occurs in quartz, very readily admit of explanation. And with regard to this latter phenomenon, the observations detailed by Sir Humphry Davy afford an additional confirmation of the theory in question.

We may explain in the same manner another phenomenon, which is more in connection with the present state of our globe. Many observations shew that the sea stood formerly at a much higher level than it does at present. The water of the sea expands, if the temperature be elevated more than the land. Admitting that the surface of the earth has a temperature of 80° of Reaumur, and that the mean depth of the sea may be 96,000 feet, the height of the sea would then be 4000 feet higher than it is at present. If we suppose, as may be done without committing any great error, that the expansion of the primitive mountains is equal to that of glass, and that they have been at a temperature of 200°, and even at a much lower one, the water of the sea would cover the secondary mountains, in which we find the remains of marine animals. This explanation of the former height of the sea appears very simple, because the elevated temperature of the earth may have resulted either from its original state of fluidity, or from a geological revolution, which has destroyed, at the same time, the organic beings of a former period.

If primitive mountains and volcanic formations have been fluid, and have crystallised on cooling, it is necessary that we should retrace in them the same phenomena and the same laws which we still observe at the present time. If a fluid body become solid by cooling, these phenomena are differently modified, according to the chemical nature of the bodies, and according to the crystalline forms which they acquire on cooling; but the laws remain always the same. Mitscherlich says, I am in possession of some specimens which explain several of the phenomena so often shewn by basalt and volcanic formations. I do not possess artificial basalt resembling the natural columnar kind; yet the slags obtained at the furnaces of Sahla resemble basalt so perfectly, as to deceive the most experienced eye, especially as their cavities contain crystals of augite. But I have found at Fahlun a bisilicate of protoxide of iron, which has in consequence a composition analogous to that of basalt, and which has distinct joints. In this slag we perceive that the joints, which are parallel to the axis of the prism and to the lateral planes of the crystals, are always perpendicular to the plane of cooling. This is particularly observable in a specimen which was obtained by melting the slag in a mould; on crystallizing it had several planes of cooling, and the joints are parallel to each of these planes. The planes of separation in basalt present exactly the same phenomenon as this slag.

The phenomena which take place when a fluid body crystallizes may be observed in sulphur, better than in any other body. All fluid bodies, however, and even water, on freezing, present the same phenomena.

If a fluid body has cooled to the point at which it begins to become solid, for example, sulphur, in a round vessel, a crust of sulphur is not formed upon the surface of the cooled vessel, and another crust upon the surface of the sulphur itself, as might be expected; on the contrary, if a crystal be formed upon a point of the inner surface of the vessel, the crystal enlarges by growing in the direction of its axis, and the mass which surrounds the crystal remains liquid, and sometimes cools, without the molecules arranging themselves in the same manner as the crystal already formed. On examining the cooled mass, we observe that it shews a lamellar texture where the crystal was formed, and that the mass which surrounded it does not shew this texture in the same degree. This explains how veins of large-granular granite traverse a small-granular granite, as well as other phenomena of the same nature.

This observation also affords an explanation of another phenomenon. If the half of the liquid mass has become solid, and if the fluid part be poured off, we obtain isolated crystals, which have been formed in the fluid mass. If the fluid part be not poured off, and be permitted to cool slowly, it contracts, as is the case with most bodies, and the contraction produces the same effect as the decantation; small cavities will be formed, and these will be traversed and covered over with distinct crystals. We also observe this phenomenon in the geodes of primitive and volcanic mountains, in which the crystals they contain are of the same minerals as those of which the mountains themselves are composed.

Note E, p. 23.

ON THE DISTRIBUTION OF BOULDER STONES IN SCOTLAND, HOLLAND, GERMANY, SWITZERLAND, AND AMERICA.

Numerous large blocks are met with in almost every country of Europe, and frequently far removed from their original situations. This is frequently the case in Scotland: thus, in the Edinburgh district, we have numerous blocks of primitive rocks, of which no fixed rocks occur nearer than in our Highland mountains.

In the north of Holland, Germany, and the countries bordering on the Baltic, enormous fragments of granite and syenite are scattered within certain limits. According to Humboldt, it seems to be now proved, that they have been carried southward, with a distribution like that of radii from a centre, from the Scandinavian peninsula, during some of the ancient revolutions of our globe, and that they have not originally belonged to the granitic chains of the Hartz and Saxony, which they approach without, however, actually attaining their basis[374]. Born, says Humboldt, on the sandy plains of the Baltic, and until the age of eighteen, not knowing any other rock than these scattered blocks, I could not but feel curious to know whether the new world presented any thing of a similar nature. I was surprised not to find a single block of this description in the Llanos of Venezuela, although the immense plains were immediately bordered to the south by a group of mountains entirely granitic[375], and which presents, in its broken and almost columnar peaks, traces of the most violent action[376]. Towards the north, the granitic chain of the Silla of Caracas and of Portocabello is separated from the Llanos, by a range of mountains which are schistose between Villa de Cura and Parapara, and calcareous between the Bergantin and Caripe. I was equally struck with the same absence of blocks upon the banks of the Amazon. La Condamine had already affirmed, that from the Pongo of Manseriche to the strait of Pauxis, not the smallest stone was to be observed. Now, the basin of the Rio Nigro and of the Amazon is also but a Llano, a plain like those of Venezuela and Buenos Ayres, the difference consisting only in the state of the vegetation. The two Llanos, situated at the northern and southern extremities of South America, are covered with gramineÆ; they are Savannas destitute of trees. The intermediate Llano, that of the Amazon, exposed to almost continual equatorial rains, is a thick forest. I do not remember to have heard that the Pampas of Buenos Ayres or the Savannas of the Missouri[377] and New Mexico contain granitic blocks. The absence of this phenomenon appears general in the new world. It is probably equally so in the Sahara in Africa; for we must not confound rocky masses which pierce the soil in the midst of the desert, and of which mention has often been made by travellers, with mere scattered fragments. These facts seem to prove, that the blocks of Scandinavian granite, which cover the sandy plains on the southern side of the Baltic, in Westphalia, and in Holland, are owing to a particular debacle which proceeded from the north, to a purely local catastrophe. The old conglomerate (grÈs rouge), which covers a great part of the Llanos of Venezuela and of the basin of the Amazon, contains, without doubt, fragments of those same primitive rocks of which the neighbouring mountains are composed; but the convulsions of which these mountains present undoubted evidences, do not seem to have been accompanied with circumstances favourable to the transportation of great blocks. This geognostic phenomenon is so much the more unexpected, that nowhere in the world does there exist a plain so continuous, and which is prolonged with fewer interruptions to the abrupt declivity of a purely granitic cordillera. Before my departure from Europe, says Humboldt, I had already been struck with the observation that there are no primitive blocks in Lombardy, nor in the great plain of Bavaria, which is the bottom of an ancient lake, having an elevation of 250 fathoms above the level of the ocean. This plain is bounded on the north by the granites of the Upper Palatinate, and on the south by the alpine limestones, transition clay-slates, and mica-slates of the Tyrol.

Boulders, or loose blocks of alpine rocks, are found in the lower part of the Alpine valleys, which terminate in the great principal valley that stretches between the Alps and the Jura, from the Lake of Geneva to the Lake Constance; and are also found almost every where in this great principal valley. They are sometimes met with 4000 feet above the level of the sea, on the side of the Jura, facing the Alps, and also in considerable numbers in many of the valleys of the Jura itself. These blocks occur only on the surface, never in any solid rock, and no one ever met with them in the subjacent strata of sandstone, marl, or conglomerate of the hills and valleys, interposed between the Alps and the Jura; but they are sometimes found deep in the soil, or imbedded or surrounded with the debris formed by rivers.

The traveller is often surprised by the enormous magnitude of these loose blocks, some of them being calculated to contain 50,000 cubic feet. The smaller masses are distinguished from those brought down by rivers, by their position, that is, their occurring on heights and acclivities, where no river could ever have run. They may also be confounded with blocks from decaying conglomerate; hence it is proper to be on our guard, not only to distinguish these blocks from those derived from conglomerate rocks, but also from the rolled masses belonging to river courses.

The height at which they are found does not appear to have any relation to their magnitude, for we often find very large blocks at considerable heights, and also in deep valleys; and we also meet with small masses as well in the bottoms of valleys, as high up on the mountains.

They occur sometimes in heaps, or dispersed in single blocks; but these relations have no connection with their magnitude, because we often find large and small masses in the same heap, and single, large, and small, blocks on mountain summits, and in the bottoms of valleys. The smaller blocks are more or less rounded, but seldom so much so as the boulders of rivers, which have been exposed to long continued friction. The larger blocks are indeed angular, but not sharp edged. But in examining this relation, we must carefully distinguish whether or not the angles or edges are original, or have been produced by subsequent, natural, or artificial causes. Very often masses of this description are blasted with gunpowder, either with the view of clearing the fields, or of obtaining stones for building; and these, if left on the ground, may lead into error.

These blocks vary in their nature, some being of the primitive class, while others belong to those of the transition and secondary classes. In general, they appertain to rock formations, situated nearer to the central alpine chains than those of the places where they are found. Thus, no rocks of the transition class occur in gneiss valleys; no alpine limestone in transition valleys; and, in general, nowhere but in Jura, do blocks of Jura limestone make their appearance. Therefore, all the loose blocks of rocks between the Jura and the Alps, belong to the strata of the high chains of the Alps.

But these blocks have different characters in different districts. The loose blocks which occur in the river basin of the Rhone, and the Lake of Geneva, are quite different from those which lie strewed about in the river basin of the Rhine. These, again, are equally different from the loose blocks of the river basin of the Aare, as those of the Aare are from the blocks of the Lake of Zurich, and the valley of Limmat; and these in their turn are equally well distinguished from the great accumulations in the valley of the Reuss. It rarely happens that intermixtures take place among these different accumulations of debris, and this is a circumstance which must be attended to in our investigation.

It results from an accurate comparison of these loose blocks with those mountain rocks which occur in extensive chains in the high Alps; that the loose blocks of every known river basin agree with the rocks which form the sides of the upper parts of those high Alpine valleys, which are in immediate connection with these great water basins. Thus the loose blocks of the water basin of the Rhine are similar to the rocks of Bundten. We find in the Lake of Zurich, and in the Limmat valley, the rocks of the Glarner land in loose blocks. The debris in the basin of the Reuss consists of rocks of the mountains from which the Reuss takes its rise. The loose blocks of the water basin of the Aare are similar to the mountain rocks of the high Alps of Bern; and the loose blocks, found in the course of the Rhone, occur in fixed rocks in the Vallais.

It thus appears that the loose blocks are by no means irregularly dispersed over the great valley between the Alps and the Jura, but are distributed in the direction of distinct water basins. It also appears, that the loose blocks are not irregularly distributed in these different basins; on the contrary, that, in some parts of the basin, they are accumulated in great numbers; in other places they are rare, and in some situations none occur.

From the preceding observations, we may obtain some hints of importance in respect of the cause of this remarkable phenomenon. These loose blocks already occur in the alpine valleys, which open into the great valley, between the Alps and the Jura. They are found more abundantly in the wide parts of valleys immediately below the narrow or contracted passes, and few occur in the narrow, steep, and rocky parts of the valleys.

Loose blocks are found, at a greater or less height, in the smaller lateral valleys that open into the transverse alpine valleys, which terminate in the great valley between the Alps and the Jura. If these lateral valleys form passes (which lead over into other valleys by a lowering of the high mountain chain), which are not more than 4000 feet above the level of the sea, loose blocks occur, not only in these passes, but also more or less widely distributed in the opposite valleys. In the great principal valley which stretches between the Alps and the Jura, from the Lake of Geneva to beyond the Lake Constance, we find these loose blocks dispersed over all the hills whose elevation is not more than 3000 feet above the level of the sea; but even here the distribution of the blocks is not entirely irregular. The largest are found on such hills and acclivities as are opposite the mouths of the alpine valleys, in the great principal valley. The blocks are frequently found higher on such acclivities, than on the sides of those valleys which may be considered as a continuation of the alpine valleys. The loose blocks are found every where on that acclivity of the Jura range which is opposite to the Alps, and they are found highest and largest in those places which are directly opposite the mouths of the alpine valleys. In such places, the blocks again attain an elevation of nearly 4000 feet above the level of the sea; whereas, in the intermediate places, which are most remote from the places opposite the mouths of the alpine valleys, the blocks seldom reach at a height of 2000 feet above the level of the sea.

In those places where the Jura chain branches into the great valley between the Jura and the Alps, loose blocks are found in the valleys behind the projecting chains. The Jura range is sometimes intersected in places opposite to the Alps; and it is remarked, that loose blocks are met with in the valleys behind these intersected portions of the range; and that, when loose blocks occur in the Jura range, at a distance from the Alps, it is only in such places as are directly opposite to the intersected portions of the chain opposite to the Alps.

The circumstance of the non-occurrence of these blocks in the sandstone, marl, and nagelfluh, which occupy the great valley between the Alps and the Jura, proves that that revolution of our globe, by which these were dispersed, took place after the formation of these rocks, and may therefore have belonged to one of the latest changes which have contributed to the present form of the earth’s surface.

When we compare the relations of the alluvium of the rivers in valleys with those of the loose blocks, their similarity must strike every one. Thus, rolled masses are seldom deposited in those places where a river forces its way through a narrow passage; but where an expansion takes place, owing to the distance of the banks increasing, the rolled masses are sometimes accumulated in whole banks. The same loose blocks seldom occur in the narrow passages of the transverse valleys in the Alps; but as soon as widenings of the valleys take place below these narrowings, the blocks occur in abundance.

If, during a flood, a rupture takes place in the banks of a river, where it is contracted, a part of the stream will flow out by the lateral opening, and carry along with it rolled masses, even when the opening in the bank does not reach to the bottom of the bed of the river; for the mountain stream, loaded with boulders, carries them not merely in single masses along its bottom, but the flood-water of the stream generally attacks large sandbanks, or older beds of rolled masses, and carries along with it, accompanied with a terrible noise, whole masses, forces them over the lower banks, or through the chasm in the bank, and often deposites them several feet high, on an immediately succeeding widening of the river’s course.

In the same manner, we observe loose blocks deposited on high situations in the lateral valleys of the great transverse valleys, and dispersed over the passes into the neighbouring valleys. The height of the lateral deposites of loose blocks, and their position in the passes, and their passing into neighbouring valleys, are facts which assist us in judging of the extent of the power that may have acted during their transportation.

The striking agreement observable in the phenomena of the distribution of the loose blocks from the interior Alpine valleys to the interior valleys of the Jura, with those in the rolled masses carried along by rivers, must lead every one, who reflects on this interesting phenomenon, to the hypothesis, that these blocks may have been deposited in their present situations by an overwhelming flood, which burst from the Alps. It is true that this opinion is liable to many objections; but still it contains a more plausible explanation of the phenomenon than any other with which we are acquainted.

The loose blocks, in the different river-districts, being in general separated from each other, or if any intermixture takes place of the rolled masses of one valley with that of another, it being only on their edges, it is highly probable that the floods which burst from these valleys, and carried along with them the masses of rocks, may have been simultaneous, by which the flow of the one basin would bound and limit that of the other, and thus prevent the water-flood of one basin flowing into the neighbouring ones.

The contemporaneous occurrence of these different floods from the Alpine valleys, can alone, on this hypothesis, explain why this aqueous flood was so generally and so highly accumulated in the great valleys between the Alps and the Jura, as to reach the height of most of the sandstone mountains, and to a great elevation in the Jura, where many blocks are found deposited. But if the contemporaneous occurrence of these floods is proved by the facts already enumerated, to what cause are we to refer this simultaneous bursting of floods of water from so many Alpine valleys?

We observe, on the north-western side of the chain of the Alps, numerous openings, which, by their structure, seem to point out the action of violent floods. Let us suppose the numerous valleys, in the districts already described, closed at their present entrances, or openings, as would seem from their structure to have been formerly the case; the consequence of this arrangement would be the filling of the Alpine valleys with water, to the height of the lowest passes among the mountains, and thus an enormous accumulation of water would take place. This great body of water, if let loose at once, by the bursting of the lower extremities of the valleys, would form a flood which would sweep across the sandstone mountains, between the Alps and the Jura range, and even ascend high on the Jura itself. This flood of water, moving, probably, at the rate of 200 feet in a second, and loaded with debris of rocks, would carry masses, even these having a magnitude of 50,000 cubical feet, some thousand feet high, on the Jura range[378]. Geologists maintain, that the blocks or boulders met with in other countries, and arranged as those in Switzerland, have been deposited where we now find them, by the bursting of lakes; while those found on the shores of the Baltic, are conjectured to have been transported by a great rush of water caused by the sudden elevation of the land of Scandinavia. Another opinion has its advocates, which maintains that these boulders have been spread over different countries by the waters of the deluge.

Note F, p. 26.

ON THE ALLUVIAL LAND OF THE DANISH ISLANDS IN THE BALTIC, AND ON THE COAST OF SLESWIGH.

In this section, Cuvier gives a clear and distinct account of several kinds of alluvial formations. M. De Luc, in the first volume of his Geological Travels, describes the alluvial formations that cover and bound many of the islands in the Baltic, and upon the coast of Denmark, and gives so interesting an account of the modes followed by the inhabitants, in preserving these alluvial deposites, that we feel pleasure in communicating it to our readers.

“During my stay at Husum, I had the advantage of passing my evenings very agreeably and profitably at the house of M. Hartz, with his own family, and two Danish officers, Major Behmann, commandant at Husum, and Captain Baron de Barackow. The conversation often turned on the objects of my excursions, and particularly on the natural history of the coasts and of the islands; respecting which, M. Hartz obligingly undertook to give me extracts from the chronicles of the country. This led us to speak of the Danish islands; and those officers giving me such descriptions of them, as were very interesting to my object, I begged their permission to write down, in their presence, the principal circumstances which they communicated to me. These will form the first addition to my own observations; I shall afterwards proceed to the information which I obtained from M. Hartz.

The two principal islands of the Danish Archipelago, those of Funen and Seeland (or Zeeland), as well as some small islands in the Kattegate, namely, Lenoe, Anholt, and Samsoe, are hilly, and principally composed of geest[379]; and in these are found gravel and blocks of granite, and of other stones of that class, exactly in the same manner as in the country which I have lately described, and its islands in the North Sea. On the borders of the two first of these Danish islands, there are also blocks in the sea; but only in front of abrupt coasts, as is the case with the islands of Poel and Rugen, and along the coasts of the Baltic. The lands added to these islands of geest are in most part composed of the sand of the sea, the land-waters there being very inconsiderable; and to the south of them have been formed several islands of the same nature, the chief of which are Laland and Falster, near Seeland. These, like the marsh islands in the North Sea, are sand-banks accumulated by the waves, and, when covered with grass, continuing to be farther raised by the sediments deposited between its blades. In the Baltic, where there are no sensible tides, such islands may be inhabited without dikes, as well as the extensions of the coasts; because, being raised to the highest level of that sea, while their declivity under water is very small, and being also more firm in their composition, the waves die away on their shores; and if, in any extraordinary case, the sea rises over them, it leaves on them fresh deposits, which increase their heights. These soils are all perfectly horizontal, like those added to the coasts of the Continent.

Some of these islands approach entirely, or in part, to the nature of that of Rugen. This island of Seeland, on that side which is called Hedding, has a promontory composed of strata of chalk with its flints. The island of Moen (or Mona), on the south of the latter, has a similar promontory near Maglebye and Mandemark; and the island of Bornholm, the easternmost of those belonging to Denmark, contains strata of coal, covered by others of sandstone. Phenomena like these, evident symptoms of the most violent catastrophes at the bottom of the ancient sea, proceeding, as I think I have clearly shewn, from the subsidence and angular motions of large masses of strata, which must have forced out the interior fluids with the utmost impetuosity, it is not surprising that so many fragments of the lowermost strata are found dispersed over this great theatre of ruins.

I now proceed to the details which I received from M. Hartz; beginning by a specific designation of the islands dependent on the province of Sleswigh, such as they are at present, belonging to the three classes already defined. To commence from the north; Fanoe, Rom, Sylt, and Amrom, were originally islands of the same nature as the neighbouring continent, but have been since extended by marsches[380]. The soil of these islands, with its gravel and blocks of primordial stones, was at first barren, as the geest is naturally every where; but is become fertile by manure, of which there has been no deficiency, since those grounds have been surrounded with marsch, where the cattle are kept in stables during the winter. In the island of Sylt, there are spaces consisting of moor, but its head of land, which extends on the south as far as Mornum, is composed entirely of marsch, and is bordered with dunes towards the open sea, because, the sediments of the rivers not reaching any farther, the sea-sand impelled against it by the waves remains pure, and is thus raised by the winds in hillocks on the shore. The shallow bottom of the sea, between this island and that of Fora, is of geest: at low water, it may be passed over on foot; and there are found on it gravel and blocks of granite. But on the same side of Fora there is a great extent of marsch, beginning from St Laurencius. Among the islands consisting entirely of marsch and surrounded with dikes, the most considerable are Pellworm and Nord Strand; and among the Halligs, or those inhabited without dikes, the chief are Olant, Nord-marsh, Langne, Groode, and Hooge.

Such are the islands on this coast, in their present state, now rendered permanent by the degree of perfection at which the art of dike-making is arrived. But, in former times, though the original land was never attacked by the sea, which, by adding to it new lands, soon formed a barrier against its own encroachments, the latter, and the islands composed of the same materials, were subject to great and sudden changes, very fatal to those who were engaged to settle on them by the richness of their soil, comparatively with the continental. The inhabitants, who continued to multiply on them during several generations, were taught, indeed, by experience, that they might at last be invaded by the element which was incessantly threatening them; but having as yet no knowledge of natural causes, they blindly considered those that endangered them as supernatural, and for a long time used no precautions for their own security. They were ignorant of the dreadful effects of a certain association of circumstances, rare indeed, but, when occurring, absolutely destructive of these marsches. This association consists of an extraordinary elevation of the level of the North Sea, from the long continuance of certain winds in the Atlantic, with a violent storm occurring during the tides of the new or full moon; for then the sea rises above the level of all the marsches; and before they were secured against such attacks, the waves rolling over them, and tearing away the grass which had bound their surface, they were reduced to the state of mere banks of sand and mud, whence they had been drawn, by the long course of ordinary causes. Such were the dreadful accidents to which the first settlers on these lands were exposed; but no sooner were they over, than ordinary causes began again to act; the sand-banks rose; their surface was covered with grass; the coast was thus extended, and new islands were formed; time effaced the impression of past misfortunes; and those among the inhabitants of these dangerous soils, who had been able to save themselves on the coast, ventured to return to settle on them again, and had time to multiply, before the recurrence of the same catastrophes.

This has been the general course of events on all the coasts of the North Sea, and particularly on those of the countries of Sleswigh and Holstein. It is thus that the origin and progress of the art of dikes will supply us with a very interesting chronometer in the history of the continent and of man, particularly exemplified in this part of the globe. A Lutheran clergyman, settled in the island of Nord Strand, having collected all the particulars of this history which the documents of the country could afford, published it in 1668, in a German work, entitled The North Frisian Chronicle. It was chiefly from this work, and from the Chronicle of Dankwerth, that M. Hartz extracted the information which he gave to me, accompanied by two maps, copied for me, by one of his sons, from those of Johannes Mayerus, a mathematician; they bear the title of Frisia Cimbrica; one of them respecting the state of the islands and of the coast, in 1240, as it may be traced in the chronicles, and the other, as it was in 1651.

According to these documents, the first inhabitants of the marsches were Frisii or Frisians, designated also under the names of Cimbri and Sicambri: the latter name, M. Hartz conjectures, might come from the ancient German words Seekampfers, i. e. Sea-warriors; the Frisians being very warlike. These people appear to have had the same origin with those, who, at a rather earlier period, took possession of the marsches of Ost-Frise (East-Friesland), and of that Friesland which forms one of the United Provinces; but this common origin is very obscure. Even at the present day, the inhabitants of the marsches, from near Husum to Tondern, or Tunder to the North, though themselves unacquainted with it, speak a language which the other inhabitants of the country do not understand, and which is supposed to be Frisian. It is the same at a village in the peninsula of Bremen, by which I have had occasion to pass.

The Sicambri or North Frisians, are traced back to some centuries before the Christian era. At the commencement of that era, they were attacked by Frotho, King of Denmark, and lost a battle, under their king Vicho, near the river Hever. Four centuries afterwards they joined the troops of Hengist and Horsa. In the year 692, their king Radebot resided in the island of Heiligeland. Charles Martel subdued them in 732; and some time afterwards they joined Charlemagne against Gottric, King of Denmark. These are some of the circumstances of the history of this Frisian colony, recorded in the chronicles of which I have spoken; but the history here interesting to us is that of the lands whereon they settled.

It appears that these people did not arrive here in one body, but successively, in the course of many years: they spread themselves over various parts of the coasts of the North Sea, and even a considerable way up the borders of the Weser and the Elbe; according to documents which I have mentioned in my Lettres sur l’Histoire de la Terre et de l’Homme. These new settlers found large marsches, formed, as well in the wide mouths of those rivers as along the coasts, and around the original islands of geest; especially that of Heiligeland, the most distant from the coast, and opposite the mouth of the Eyder. Of this island, which is steep towards the south, the original mass consists of strata of sandstone; and at that time its marsch extended almost to Eyderstede: there were marsches likewise around all the other original islands; besides very large islands of pure marsch in the intervals of the former.

All these lands were desert at the arrival of the Frisians; and the parts on which they established their first habitations, to take care of their breeds of horses and cattle feeding on the marsches, were the original eminences of the islands; on that of Heiligeland they built a temple to their great goddess Phoseta, or Fosta. When they became too numerous to confine themselves to the heights, their herds being also greatly multiplied, they ventured to begin inhabiting the marsches; but afterwards, some great inundations having shewn them the dangers of that situation, they adopted the practice followed by those who had settled on the marsches of the province of Groningen, and still continued on the Halligs; that of raising artificial mounts called werfs, on which they built their houses, and whither they could, upon occasion, withdraw their herds; and it likewise appears, that, in the winter, they assembled in greater numbers on the spots originally the highest, in the islands, as well as on some parts of the coasts.

Things continued in this state for several centuries; during which period, it is probable that the inhabitants of these lands were often, by various catastrophes, disturbed in the enjoyment of them, though not discouraged. But in 516, by which time these people were become very numerous, more than 600 of them perished by one of the concurrences of fatal circumstances already defined. It was then that they undertook the astonishing enterprise of enclosing these lands. They dug ditches around all the marsches, heaping up on their exterior edge the earth which was taken out; and thus they opposed to the sea, dikes of eight feet in height. After this, comprehending that nothing could contribute more to the safety of their dwellings, than to remove the sea to a greater distance, they undertook, with that view, to exclude it from the intervals between the islands, by uniting, as far as should be possible, those islands with each other. I will describe the process by which they effected this, after I shall have recalled to attention some circumstances leading to it.

From all that I have already said of the fore-lands, and of the manner in which they are increased, it may be understood, that the common effects of the waves and of the tides is to bring materials from the bottom of the sea towards the coasts; and that the process continues in every state of the sea. The land winds produce no waves on the coasts, which can carry back to the bottom of the sea what has been brought thence by the winds blowing against the shore; and as for the tides, it may have been already comprehended (and shall soon be proved), that the ebb carries back but very little of what has been brought by the flood. So that, but for some extraordinary circumstances, the materials continually impelled towards the shore, which first form islands, would at last unite against the coast in a continuous soil. The rare events, productive of great catastrophes, do not carry back these materials towards the bottom of the sea; they only, as it has been said before, ravage the surface, diminishing the heights, and destroying the effect of vegetation. These, then, were the effects against which it was necessary to guard.

I now come to the plan of uniting the islands, formed by these early inhabitants. They availed themselves for that purpose of all such parts of the sand-banks as lay in the intervals between the large islands, and were beginning to produce grass. These, when surrounded with dikes, are what are called Hoogs; and their effects are to break the waves, thus diminishing their action against the dikes of the large islands, and, at the same time, to determine the accumulation of the mud in the intervals between those islands. In this manner a large marsch island, named Everschop, was already, in 987, united to Eyderstede by the point on which Poppenbull is situated; and in 995, the union of the same marsches was effected by another point, namely, that of Tetenbull. Lastly, in the year 1000, Eyderstede received a new increase by the course of the Hever, prolonged between the sand banks, being fixed by a dike; but the whole still remained an island. This is an example of the manner in which the marsch islands were united by the hoogs; and the chronicle of the country says, that, by these labours, the islands were so considerably enlarged in size, and the intervals between them so much raised, that, at low water, it was possible to pass on foot from one to the other. The extent of these marsches was so great on the coast of Sleswigh alone, that they were divided into three provinces, two of which comprehended the islands, and the third comprised the marsches contiguous to the coast; and the same works were carried on upon the marsches of the coast of Holstein.

But the grounds thus gained from the sand-banks were very insecure; these people, though they had inhabited them more than ten centuries, had not yet understood the possibility of that combination of fatal circumstances above described, against which their dikes formed but a very feeble rampart; the North Sea, by the extraordinary elevations of its level, being much more formidable in this respect than the ocean, where the changes of absolute level are much less considerable. I shall give an abridged account of the particulars extracted by M. Hartz from the chronicle of Dankwerth, relative to the great catastrophes which these marsches successively underwent, previously to the time when experience led to the means necessary for their security.

In 1075, the island of Nord Strand, then contiguous to the coast, particularly experienced the effect of that unusual combination of destructive causes; the sea passing over its dike, and forming within it large excavations like lakes. In 1114 and 1158, considerable parts of Eyderstede were carried away; and in 1204, the part called Sudhever in the marsch of Uthholm was destroyed. All these catastrophes were fatal to many of the marsch settlers; but in 1216, the sea having risen so high that its waves passed over Nord Strand, Eyderstede, and Ditmarsch, near 10,000 of their inhabitants perished. Again, in 1300, seven parishes in Nord Strand and Pellworm were destroyed; and in 1338, Ditmarsch experienced a new catastrophe, which swept away a great part of it on the side next Eyderstede: the dike of the course of the Eyder between the sand-banks was demolished, and the tides have ever since preserved their course throughout that wide space. Lastly, in the year 1362, the isles of Fora and Sylt, then forming but one, were divided, and Nord Strand, then a marsch united to the coast, was separated from it.

During a long time, the inhabitants who survived these catastrophes, and their successors, were so much discouraged, that they attempted nothing more than to surround with dikes like the former such spaces of their meadow-land as appeared the least exposed to these ravages, leaving the rest to its fate. But the common course of causes continually tending to extend and to raise the grassy parts of the sand-banks, and no extraordinary combination of circumstances having interrupted these natural operations, later generations, farther advanced in the arts, undertook to secure to themselves the possession of those new grounds. In 1525, they turned their attention to the indentations made, during the preceding catastrophes, in the borders of the marsches; the waves, confined in these narrow spaces, sometimes threatening to cut their way into the interior part. In the front of all the creeks of this kind they planted stakes, which they interlaced with osiers, leaving a certain space between the lines. The waves, thus broken, could no longer do injury to the marsch; and their sediments being deposited on both sides of this open fence, very solid fore-lands were there formed. In 1550, they raised the dikes considerably higher, employing wheelbarrows, the use of which was only then introduced. For this purpose, they much enlarged and deepened the interior canals, in order to obtain more earth, not merely to add to the height of the dikes, but to extend their base on the outer side. At last they began to cover these dikes with straw-ropes; but this great preservative of dikes was at first ill managed; and the use of it was so slowly spread, that it was not adopted in North Strand and in Eyderstede, till about the years 1610 and 1612.

Before that time, however, the safety of the extensive soil of the latter marsch had been provided for in a different manner. I have said above, that, when the isles of Everschop and Utholm had been united to it, the whole together still formed but one large island; now, in this state, it was in as great danger on the side towards the continent, as on that open to the sea; because two small rivers, the Trene and the Nord Eyder, discharging themselves into the interval between it and the land, and by preserving their course to the sea, this interval was thus kept open to tempest, sometimes from the side of the Hever, sometimes from that of the Eyder; and the waves, beating against the geest, were thence repelled upon the marsch. The inhabitants, seeing that the expence of remedying these evils would be greater than they could afford, while at the same time it was indispensable to their safety, addressed themselves to their bishop and to their prefect, of whom they requested pecuniary assistance; and having obtained it they first undertook the great enterprise of carrying the Trene and the Nord Eyder higher up into the Eyder; keeping their waters, however, still separate for a certain space, by a dam with a sluice, in order to form there a reservoir of fresh water; the tides ascending up the Eyder above Frederickstadt. They were thus enabled to carry on the extremities of the dike on both sides to join the geest; and the interval between the latter and the marsch was then soon filled up, there being only left at their junction the canal above described which receives the water of the geest, and, at low water, discharges them from both its extremities by sluices. At the same time, the islands of Pellworm and Nord Strand were united with each other by means of eight hoogs; and the sandy marsches of which I have spoken, contiguous to the geest, on the north of that of Husum, were inclosed with dikes.

After the dikes had been thus elevated, and their surface rendered firm by the straw ropes, though the latter were not yet properly fixed, the inhabitants of the marsches for some time enjoyed repose; but on the 11th October 1634, the sea, rising to an excessive height, carried away, during a great tempest, the hoogs which had produced the junction between Pellworm and Nord Strand, these having ever since continued distinct islands; it also violently attacked Ditmarsch; and its ravages extended over the whole coast, as far as the very extensive new lands of Jutland. Princes then came forward zealously to the relief of their subjects. In particular, Frederick III., Duke of Sleswigh, seeing that the inhabitants of Nord Strand were deficient both in the talents and in the means necessary for the reparation and future security of that large island, and knowing that the art of dikes had made greater progress in Holland, because of the opulence of the country, addressed himself to the States-General, requesting them to send him an engineer of dikes, with workmen accustomed to repair them; and this was granted. The dikes of Nord Strand were then repaired in the most solid manner; and the Dutch engineer, seeing the fertility of its soil, advised his sons upon his death-bed, to purchase lands and settle there, if the Duke would grant them the free exercise of their religion; they being Jansenist catholics, and the inhabitants of the island Lutherans. The Duke agreed to this, on condition that they and their posterity should continue to superintend the works carried on upon the dikes; to which they engaged themselves. From that time the art of dikes, and particularly that part of it which consists in covering them solidly with straw, has become common to all the marsches; and the Dutch families, which have contributed to this fortunate change, continue to inhabit the same island, and to enjoy the free exercise of their religion.”

Note G, p. 28.

ON THE SAND-FLOOD.

In different parts of Scotland, as in Aberdeenshire, Hebrides, and Shetland Islands, there are examples of the natural chronometer mentioned in the text. In Morayshire there is a striking example of the sand-flood, concerning which the following details have been furnished by my young friend the Rev. Mr Ritchie.

Sand-Flood in Morayshire.

“Westward from the mouth of the river Findhorn in Morayshire, a district, consisting of upwards of ten square miles of land, which, owing to its extreme fertility, was once termed the Granary of Moray, has been depopulated and rendered utterly unproductive by the sand-flood. This barren waste may be characterised as hilly; the accumulations of sand composing these hills frequently varying in their height, and changing their situation.

There is historical evidence, that, in the year 1097, the Moray Firth overflowed the low country on its southern shore, and threw out sand. But the destruction of the barony of Coubine (which includes the greater part of the desert mentioned above) was long subsequent to this, as might be proved from the inscription on a tombstone in the church yard of Dyke. From historical notices, also, in regard to the Kinnairds of Coubine, preparing for publication, it appears that the eruption of sand commenced about the year 1677; that its progress was gradual; that, in 1697, not a vestige was to be seen of the manor-place, orchards, and offices of Coubine; that two-thirds of the barony were already ruined, and that the sand was daily gaining ground.

This sand, which overwhelmed Coubine, came from Mavieston, situated on the shore, about seven miles west from the mouth of the Findhorn, where, from time immemorial, there have been large accumulations of sand. The sands at Mavieston had formerly been covered with vegetation. In an act of the Scottish Parliament, dated 16th July 1695, for the preservation of lands adjacent to sand-hills, it is stated, that the destruction of Coubine “was occasioned by the bad practice of pulling bent and juniper.” Having been thus set at liberty, the sand moved towards the north-east, as appears from the desolation which marks its progress. The moving cause is the wind. I have had opportunities of witnessing the effect of the wind on the loose sand. When the breeze is moderate it carries along with it successive waves of sand, each wave (if I may be allowed the expression) being of a small size, and moving with greater or less velocity, in proportion to the strength of the breeze, and presenting a very beautiful appearance. When the wind is high the heavier particles are drifted forwards, the more minute are raised to a considerable height in the atmosphere, occasioning no small inconvenience to the spectator, who finds his ears and nostrils filled with sand. The movements of the sand are still towards the north-east. In the winter of 1816 a large portion of Binsness, the only remaining farm on the west side of the Findhorn, situated in the line of the sand’s progress, was overwhelmed. Since that period large accumulations of sand have disappeared altogether, and rich soil, marked with the plough, has been left bare, after having been buried for upwards of a century.

The very minute particles, which, as has been stated, the wind raises to a considerable height, are occasionally carried across the Bay of Findhorn. In the statistical account of Dyke, the parish in which Coubine is situated, it is said, “that, at the town of Findern, in a blowing day, one may feel the sand sharply striking on his face, from the west side.” This sand, of extreme fineness, is to be seen in and around the town of Findhorn, and along the coast much rich land is said to have been covered by sand brought from the west.

The greater quantity of the sand is drifted into the river, and its effects have been very remarkable. Many years ago the mouth of the river having become blocked up with sand, it cut out for itself its present channel, which conducts it, by a more direct course, to the sea. In consequence of this, the old town of Findhorn had changed its situation, from the east to the west side of the river, and its site has since been covered by the sea. Previous to this, however, the inhabitants, carrying with them the stones of their former houses, had removed across the river, and erected the present village. On the retiring of the tide from the bay, the river almost disappears, being swallowed up by the sand, and quick-sands are formed. The effect resulting from the same cause, the drifting in of the sand is very different at high water. In consequence of the channel of the river having been filled up, the bay has increased in breadth. The sand constantly carried down by the river has formed a bar, which prevents the entrance of large vessels; and the river, probably owing to its increased breadth, and this bar depriving it of the impetus acquired in the course of its descent, is, at spring-tides, unable to force its way into the sea, when it is made to flow back, and inundate a considerable extent of carse-land situated at the head of the bay. It was at one time proposed to render the river navigable by dredging. And it is proposed to endeavour to save the adjoining carse-land, which is of the richest quality, from the monthly inundation to which it is at present subject, by building a wall along the river side.

I venture to suggest, that the plan Nature employs for fettering down sand should first be imitated, and that seeds of the Arundo arenaria, Elymus arenarius, and other plants, which grow readily in sand, should be, from time to time, strewed over the Mavieston Hills. The seeds of the Arundo arenaria are not always to be had; but plants might easily be procured in abundance, and be dibbled into the sand-hills. The circumstance of great accumulations of sand having of late disappeared from Coubine, has given rise to the expectation, that the barony is at no distant period to become again serviceable to man. By cutting off fresh supplies from Mavieston, this period would be accelerated, and the proposed improvements rendered comparatively easy.

There is at present little bent on Coubine. It is chiefly confined to a range of knolls, which forms the southern boundary of the sand, and protects the adjoining cultivated fields from its encroachments; and yet, notwithstanding the terrible calamity the inhabitants of Moray brought upon themselves, by the pulling of bent, this “bad practice” still prevails; this plant being in no other district of country which I have visited so generally employed for thatching cottars’ houses, and other economical purposes.”


In the Outer Hebrides the effects of the sand-flood are also considerable, as shewn in the following notice communicated by my intelligent assistant Mr Macgillivray.

Sand-Flood in the Hebrides, and other parts of Scotland.

“The bottom of the sea, along the whole west coast of the Outer Hebrides, from Barray Head to the Butt of the Lewis, appears to consist of sand. Along the shores of these islands this sand appears here and there, in patches of several miles, separated by intervals of rock, of equal or greater extent. In some places the sandy shores are flat, or very gently sloping, forming what are here called Fords; in others, behind the beach, there is an accumulation of sand to the height of from twenty to sixty feet, formed into hillocks. This sand is constantly drifting; and in several places islands have been formed by the removal of isthmi. The parts immediately behind the beach are also liable to be inundated by the sand; and in this manner most of the islands have suffered very considerable damage. Those of Pabbay and Berneray in Harris may be particularised; in the former of which, a tract of about a mile and a-half long, by half a mile in breadth, has been converted into a desert of drifting sand; and in the latter a large plain, that was formerly noted for its fertility, has been entirely swept away. The sand consists almost entirely of comminuted shells, apparently of the species which are found in the neighbouring seas. It is rather coarse in the grain; but, during high winds, by the rubbing of its particles upon each other, a sort of dust is formed, which, at a distance, resembles smoke, and which, in the Island of Berneray, I have seen driven into the sea, to the distance of upwards of two miles, appearing like a thin white fog. The cure of sand drift has been attempted in these islands in two different ways. Mr Alexander Macleod, surgeon of North Uist, is the inventor of the most efficacious method, which is that of cutting thin square turfs from the neighbouring pasture grounds, and laying them down at intervals of some inches. In the course of a very few years the turfs coalesce, and the stript ground is little the worse; for the roots remaining in it, a new vegetation rapidly springs up. The other method was introduced by Mr Macleod of Harris, and tried extensively upon his estate. It consists of planting small bundles of Arundo arenaria, at distances of about a foot and a-half. These take root, and prevent the drifting to a certain degree. But often vegetation is tardy in establishing itself, and if the turf plan be not considerably more expensive, it seems preferable, because it very effectually prevents the drift, and moreover, produces excellent pasture ground; the former of which indications, the planting system, does not completely effect, and the latter in a very imperfect degree.”

We may add, as this subject is a very interesting one, that further details, in regard to the moving sands of Scotland, will be found, on consulting the Statistical Account of Scotland, vol. xx. p. 220. In the Appendix to the Account of the parish of Dyke, vol. xx. p. 228. et seq. there is an account of the Sand-Hills of Mavieston, which overwhelmed the barony of Coubine, as mentioned in Mr Ritchie’s communication. In vol. xix. p. 622. is a notice of the shifting of two hills of the Mavieston Range 500 yards in twenty years. In vol. xxi. p. 207. is a notice of some hundred acres in Duffus’ parish covered three feet deep by drift sand; fourteen inches accumulating in one night. In Neill’s Tour in Orkney and Shetland 1804, it is observed, that, in the neighbourhood of the Castle of Noltland, in Westra, much havoc has been done by the blowing of the sand. No measures are there employed for putting a stop to this kind of devastation. In the 6th volume of the Highland Society’s Transactions will be found a report of the operations carried on in Harris, and alluded to in Mr Macgillivray’s communication. And in Dr Walker’s Account of the Hebrides, and Mr Macdonald’s Work on the Hebrides, farther details may be seen. In Jameson’s Account of the Shetland Islands, and in Shirreff and Fleming’s Reports on these islands, are also facts connected with this devastating agent. We may add, that Dr Oudney, Major Denham, and Captain Clapperton, have added to our knowledge of the blowing sands of the African deserts. The coloured engraving of the sand-hills of the African Desert in Denham, Oudney and Clapperton’s Narrative, is a striking and interesting representation of the form of the moving sand-hills of Africa.

The moving Sands of Africa and their effects are thus described in the Mercure de France for September 1809, by De Luc.

The sands of the Lybian desert, he says, driven by the west winds, have left no lands capable of tillage on any parts of the western banks of the Nile not sheltered by mountains. The encroachment of these sands on soils which were formerly inhabited and cultivated is evidently seen. M. Denon informs us, in the account of his Travels in Lower and Upper Egypt, that summits of the ruins of ancient cities buried under these sands still appear externally; and that, but for a ridge of mountains called the Lybian chain, which borders the left bank of the Nile, and forms, in the parts where it rises, a barrier against the invasion of these sands, the shores of the river, on that side, would long since have ceased to be habitable. Nothing can be more melancholy, says this traveller, than to walk over villages swallowed up by the sand of the desert, to trample under foot their roofs, to strike against the summits of their minarets, to reflect that yonder were cultivated fields, that there grew trees, that here were even the dwellings of men, and that all has vanished.

If, then, our continents were as ancient as has been pretended, no traces of the habitation of men would appear on any part of the western bank of the Nile, which is exposed to this scourge of the sands of the desert. The existence, therefore, of such monuments attests the successive progress of the encroachments of the sand; and those parts of the bank, formerly inhabited, will for ever remain arid and waste. Thus the great population of Egypt, announced by the vast and numerous ruins of its cities, was in great part due to a cause of fertility which no longer exists, and to which sufficient attention has not been given. The sands of the desert were formerly remote from Egypt; the Oases, or habitable spots, still appearing in the midst of the sands, being the remains of the soils formerly extending the whole way to the Nile; but these sands, transported hither by the western winds, have overwhelmed and buried this extensive tract, and doomed to sterility a land which was once remarkable for its fruitfulness.

It is therefore not solely to her revolutions and changes of sovereigns that Egypt owes the loss of her ancient splendour; it is also to her having been thus irrecoverably deprived of a tract of land, by which, before the sands of the desert had covered it, and caused it to disappear, her wants had been abundantly supplied. Now, if we fix our attention on this fact, and reflect on the consequences which would have attended it if thousands, or only some hundreds, of centuries had elapsed since our continents first existed above the level of the sea, does it not evidently appear that all the country on the west of the Nile would have been buried under this sand before the erection of the cities of ancient Egypt, how remote soever that period may be supposed; and that in a country so long afflicted with sterility, no idea would even have been formed of constructing such vast and numerous edifices? When these cities indeed were built, another cause concurred in favouring their prosperity. The navigation of the Red Sea was not then attended with any danger on the coasts; all its ports, now nearly blocked up with reefs of coral, had a safe and easy access; the vessels laden with merchandize and provisions could enter them and depart without risk of being wrecked on these shoals, which have risen since that time, and are still increasing in extent.

The defects of the present government of Egypt, and the discovery of the passage from Europe to India round the Cape of Good Hope, are therefore not the only causes of the present state of decline of this country. If the sands of the desert had not invaded the bordering lands on the west, if the work of the sea polypi in the Red Sea had not rendered dangerous the access to its coasts and to its ports, and even filled up some of the latter, the population of Egypt and the adjacent countries, together with their product, would alone have sufficed to maintain them in a state of prosperity and abundance. But now, though the passage to India by the Cape of Good Hope should cease to exist, though the political advantages which Egypt enjoyed during the brilliant period of Thebes and Memphis should be re-established, she could never again attain the same degree of splendour.

Thus the reefs of coral which had been raised in the Red Sea on the east of Egypt, and the sands of the desert which invade it on the west, concur in attesting this truth: That our continents are not of a more remote antiquity than has been assigned to them by the sacred historian in the book of Genesis, from the great era of the deluge.

Note H, p. 30.

Action of the Sea upon Coasts.

The ocean, in its action upon the cliffs and banks situated on the coast, breaks them down to a greater or less extent, and either accumulates the debris at their basis in the form of sea beaches of greater or less magnitude, or by currents carries it away to be deposited upon other shores, or to give rise to sand-banks near the coast, which, in the course of time, become united to the land, and thus secure it from the further action of the sea. These destroying and forming effects of the waters of the ocean are to be observed all around the coasts of this island; and beautiful examples of such actions are to be seen on the coasts of Ireland, and in many of the islands that lie to the west and north of Great Britain. In a paper read before the Wernerian Natural History Society, Mr Stevenson, engineer, mentions many facts illustrative of the destroying effects of the ocean on our coasts.—Thus he informs us that the waters of the sea are wearing away the land upon both sides of the Frith of Forth, not only in exposed, but also in sheltered situations, and the solid strata, as well as the looser alluvial formations, which owe their origin to the destroying agency of the ocean at a former period, are again yielding to its action. At Saint Andrew’s, the famous castle of Cardinal Beaton, which is said originally to have been some distance from the sea, now almost overhangs it: From St Andrew’s northward to Eden water and the River Tay, the coast presents a sandy beach, and is so liable to shift, that it is difficult to trace the change it may have undergone. It is certain, however, that, within this last century, the sea has made such an impression upon the sands of Barray, on the northern side of the Tay, that the light-houses at the entrance of the river, which were formerly erected at the southern extremity of Button-ness, have been from time to time removed about a mile and a quarter further northward, on account of the wasting and shifting of these sandy shores, and that the spot on which the outer light-house stood in the 17th century, is now two or three fathoms under water, and is at least three quarters of a mile within flood-mark.

NOTE, p. 32.

On the growth of Coral Islands.

Of all the genera of lithophytes, the madrepore is the most abundant. It occurs most frequently in tropical countries, and decreases in number and variety as we approach the poles. It encircles in prodigious rocks and vast reefs many of the basaltic and other rocky islands in the South Sea and Indian Ocean, and, by its daily growth, adds to their magnitude. The coasts of the islands in the West Indies, also those of the islands on the east coast of Africa, and the shores and shoals of the Red Sea, are encircled and incrusted with rocks of coral. Several different tribes of madrepore contribute to form these coral reefs; but by far the most abundant are those of the genera carophylla, astrea and meandrina. These lithophytic animals not only add to the magnitude of land already existing, but, according to some naturalists, they form whole islands. Dr Forster, in his Observations made during a Voyage round the World, gives an account of the formation of these coral islands in the South Sea.

All the low isles, he says, seem to me to be a production of the sea, or rather its inhabitants, the polype-like animals forming the lithophytes. These animalcules raise their habitation gradually from a small base, always spreading more and more, in proportion as the structure grows higher. The materials are a kind of lime mixed with some animal substances. I have seen these large structures in all stages, and of various extent. Near Turtle Island, we found, at a few miles distance, and to leeward of it, a considerable large circular reef, over which the sea broke every where, and no part of it was above water; it included a large deep lagoon. To the east and north-east of the Society Isles, are a great many isles, which in some parts are above water; in others, the elevated parts are connected by reefs, some of which are dry at low water, and others are constantly under water. The elevated parts consist of a soil formed by a sand of shells and coral rocks, mixed with a light black mould, produced from putrified vegetables, and the dung of sea-fowls; and are commonly covered by cocoa-nut trees and other shrubs, and a few antiscorbutic plants. The lower parts have only a few shrubs and the above plants; others still lower, are washed by the sea at high-water. All these isles are connected, and include a lagoon in the middle, which is full of the finest fish; and sometimes there is an opening, admitting a boat or canoe, in the reef, but I never saw or heard of an opening that would admit a ship.

The reef, or the first origin of these isles, is formed by the animalcules inhabiting the lithophytes. They raise their habitation within a little of the surface of the sea, which gradually throws shells, weeds, sand, small bits of corals, and other things, on the tops of these coral rocks, and at last fairly raises them above water; where the above things continue to be accumulated by the sea, till by a bird, or by the sea, a few seeds of plants that commonly grow on the sea-shore, are thrown up, and begin to vegetate; and by their annual decay and reproduction from seeds, create a little mould, yearly accumulated by the mixture with sand, increasing the dry spot on every side; till another sea happens to carry a cocoa-nut hither, which preserves its vegetative power a long time in the sea, and therefore will soon begin to grow on this soil; especially as it thrives equally in all kinds of soil; and thus may all these low isles have become covered with the finest cocoa-nut trees.

The animalcules forming these reefs want to shelter their habitation from the impetuosity of the winds, and the power and rage of the ocean; but as, within the tropics, the winds blow commonly from one quarter, they, by instinct, endeavour to stretch only a ledge, within which is a lagoon, which is certainly entirely screened against the power of both. This, therefore, might account for the method employed by the animalcules in building only narrow ledges of coral rocks, to secure in their middle a calm and sheltered place; and this seems to me to be the most probable cause of the origin of all the Tropical Low Isles, over the whole South Sea.

That excellent navigator, the late Captain Flinders, gives the following interesting account of the formation of Coral Islands, particularly of Half-way Island on the north coast of Terra Australis[381].

“This little island, or rather the surrounding reef, which is three or four miles long, affords shelter from the south-east winds; and being at a moderate day’s run from Murray’s Isles, it forms a convenient anchorage for the night to a ship passing through Torres’ Strait: I named it Half-way Island. It is scarcely more than a mile in circumference, but appears to be increasing both in elevation and extent. At no very distant period of time, it was one of those banks produced by the washing up of sand and broken coral, of which most reefs afford instances, and those of Torres’ Strait a great many. These banks are in different stages of progress: some, like this, are become islands, but not yet habitable; some are above high-water mark, but destitute of vegetation; whilst others are overflowed with every returning tide.

“It seems to me, that, when the animalcules which form the corals at the bottom of the ocean cease to live, their structures adhere to each other, by virtue either of the glutinous remains within, or of some property in salt water; and the interstices being gradually filled up with sand and broken pieces of coral washed by the sea, which also adhere, a mass of rock is at length formed. Future races of these animalcules erect their habitations upon the rising bank, and die in their turn, to increase, but principally to elevate, this monument of their wonderful labours. The care taken to work perpendicularly in the early stages, would mark a surprising instinct in these diminutive creatures. Their wall of coral, for the most part, in situations where the winds are constant, being arrived at the surface, affords a shelter, to leeward of which their infant colonies may be safely sent forth; and to this, their instinctive foresight, it seems to be owing, that the windward side of a reef exposed to the open sea, is generally, if not always, the highest part, and rises almost perpendicular, sometimes from the depth of 200, and perhaps many more fathoms. To be constantly covered with water, seems necessary to the existence of the animalcules, for they do not work, except in holes upon the reef, beyond low-water mark; but the coral, sand, and other broken remnants thrown up by the sea, adhere to the rock, and form a solid mass with it, as high as the common tides reach. That elevation surpassed, the future remnants, being rarely covered, lose their adhesive property; and remaining in a loose state, form what is usually called a key, upon the top of the reef. The new bank is not long in being visited by sea-birds: salt plants take root upon it, and a soil begins to be formed; a cocoa-nut, or the drupe of a pandanus, is thrown on shore; land birds visit it, and deposit the seeds of shrubs and trees; every high tide, and still more every gale, adds something to the bank; the form of an island is gradually assumed; and last of all comes man to take possession.

“Half-way Island is well advanced in the above progressive state; having been many years, probably some ages, above the reach of the highest spring tides, or the wash of the surf in the heaviest gales. I distinguished, however, in the rock which forms its basis, the sand, coral, and shells, formerly thrown up, in a more or less perfect state of cohesion. Small pieces of wood, pumice stone, and other extraneous bodies which chance had mixed with the calcareous substances when the cohesion began, were inclosed in the rock; and in some cases were still separable from it without much force. The upper part of the island is a mixture of the same substances in a loose state, with a little vegetable soil; and is covered with the casuarina and a variety of other trees and shrubs, which give food to parroquets, pigeons, and some other birds; to whose ancestors, it is probable, the island was originally indebted for this vegetation.”

Mr Chamisso, who accompanied Kotzebue in his voyage, has published interesting observations on this subject. He informs us that the low islands of the South Sea and Indian Ocean owe their origin principally to the operations of several species of coral. Their situation with respect to each other, as they often form rows, their union in several places in large groups, and their total absence in other parts of the same seas, induce us to conclude, that the corals have founded their building on shoals of the sea; or, to speak more correctly, on the tops of mountains lying under water. On the one side, as they increase, they continue to approach the surface of the sea, on the other side they enlarge the extent of their earth. The larger species of corals, which form blocks, measuring several fathoms in thickness, seem to prefer the more violent surf on the external edge of the reef; this, and the obstacles opposed to the continuation of their life, in the middle of a broad reef, by the amassing of the shells abandoned by the animals, and fragments of corals, are probably the reason that the outer edge of the reef first approaches the surface. As soon as it has reached such a height, that it remains almost dry at low water, the corals leave off building higher; sea-shells, fragments of coral, shells of echini, and their broken-off prickles, are united by the burning sun, through the medium of the cementing calcareous sand, which has arisen from the pulverization of the above mentioned shells into one whole or solid stone, which, strengthened by the continual throwing up of new materials, gradually increases in thickness till it at last becomes so high, that it is covered only during some seasons of the year by the high tides. The heat of the sun so penetrates the mass of stone when it is dry, that it splits in many places, and breaks off in flakes. These flakes, so separated, are raised one upon another by the waves at the time of high water. The always active surf throws blocks of coral, (frequently of a fathom in length, and three or four feet thick,) and shells of marine animals, between and upon the foundation stones; after this the calcareous sand lies undisturbed, and offers to the seeds of trees and plants, cast upon it by the waves, a soil upon which they rapidly grow, to overshadow its dazzling white surface. Entire trunks of trees, which are carried by the rivers from other countries and islands, find here, at length, a resting place after their long wanderings; with them come some small animals, such as lizards and insects, as the first inhabitants. Even before the trees form a wood, the real sea-birds nestle here; strayed land-birds take refuge in the bushes; and at a much later period, when the work has been long since completed, man also appears, builds his hut on the fruitful soil formed by the corruption of the leaves of the trees, and calls himself lord and proprietor of this new creation.

In the preceding account, we have seen how the exterior edge of a submarine coral edifice first approaches the surface of the water, and how this reef gradually assumes the properties of land; the island, therefore, necessarily has a circular form, and in the middle of it an inclosed lake. This lake, however, is not entirely inclosed; (and it could not be, for without supply from the sea it would soon be dried up by the rays of the sun,) but the exterior wall consists of a great number of smaller islands, which are separated from each other by sometimes larger, sometimes smaller spaces. The number of these islets amounts, in the larger coral islands, to sixty; and between them it is not so deep but that it becomes dry at the time of ebb. The interior sea has in the middle generally a depth of from thirty to five-and-thirty fathoms; but on all sides towards the land the depth gradually increases. In those seas where the constant monsoons prevail, where, consequently, the waves beat only on one side of the reef or island, it is natural that this side of the reef, exposed to the unremitting fury of the ocean, should be formed chiefly by broken-off blocks of coral, and fragments of shells, and first rise above the elements that created it. It is only these islands respecting the formation and nature of which we hitherto know any thing with certainty; we are almost entirely without any observations on those in the Indian and Chinese Sea, which lie in the regions of the six months’ monsoons. From the charts given of them, it is to be inferred that every side is equally advanced in formation. The lee side of such a coral reef in the Pacific Ocean, which is governed by the constant monsoons, frequently does not shew itself above the water, when the opposite side, from time immemorial, has attained perfection in the atmospheric region; the former reef is even interrupted in many places by intervals tolerably broad, and of the same depth as the inner sea, which have been left by nature, like open gates, for the exploring mariner to enter the internal calm and secure harbour. In their external form the coral islands do not resemble each other; but this, and the extent of each, probably depends on the size of the submarine mountain tops, on which their basis is founded. Those islands which have more length than breadth, and are opposed in their greatest extent to the winds and waves, are richer in fruitful islets than those whose situation is not so adapted to a quick formation. In the large island-chains, there are always some single islets which have the appearance of high land; these lie upon an angle projecting into the sea, are exposed to the surf upon two sides, consist therefore almost entirely of large blocks of coral, and are destitute of smaller fragments of shells and coral sand to fill up the intervals. They are, therefore, not adapted to support plants requiring a depth of soil, and only afford a basis to high trees, provided with fibrous roots, (as the Pisonia, Cordia Sebastiana, L.; Morinda citrifolia, L.; and Pandanus odoratissimus, L.), which, at a distance, give to these, always very small islands, the form of a hill. The inner shores of the island, exposed to the surf, consist of fine sand, which is washed up by the tide. Between the small islands under their protection, and even in the middle of the inner sea, are found smaller pieces of coral, which seek a quiet abode, form in time, though very slowly, banks, till they at last reach the surface of the water; gradually increase in extent; unite with the islands that surround them; and at length fill up the minor seas, so that what was at first a ring of islands, becomes one connected land. The islands which are so far formed, retain in the middle a flat plain, which is always lower than the wall that surrounds them on the banks; for which reason pools of water are formed in them, after a continued rain,—the only springs and wells they possess. One of the peculiarities of these islands is, that no dew falls in the evening, that they cause no tempests, and do not check the course of the wind. The very low situation of the country sometimes exposes the inhabitants to great danger, and threatens their lives when the waves roll over their islands, if it happens that the equinox and full moon fall on the same day (consequently when the water has reached its greatest height), and a storm agitates the sea at the same time. These islands are said to be also shaken by earthquakes.

MM. Quoy and Gaimard, in a lately published memoir, propose, 1st, To examine how corals raise their habitations upon rocks, and what circumstances are favourable or unfavourable to their growth. 2d, To shew that there are no islands of any extent, constantly inhabited by man, which are entirely formed of corals; and that far from raising from the depths of the ocean perpendicular walls, as has been alleged, these animals form only layers or crusts of a few fathoms thickness.

The following, according to the French naturalists, is the manner in which this addition or superposition of madrepores is effected. In the places where the heat is constantly intense, where the land is indented by bays containing shallow and quiet water, which is not liable to be agitated by great surges, or by the regular breezes of the tropics, there also the saxigenous polypi multiply. They construct their habitations on the submarine rocks, envelope these rocks in whole or in part, but do not form them properly speaking. Thus, all those reefs, those girdles of madrepore, which are so frequently met with in the South Sea, to the leeward of islands, are shoals depending upon the conformation of the original ground, which will be perceived to belong to it when the direction of the mountains and hills has been attentively observed. It is always where the slopes are gentle, and the sea shallowest, that the greatest masses of madrepores are found. They sprout up if it is calm; in the contrary case, they form only scattered tufts, belonging to species which seem to be least affected by the agitation of the waters.

It has been said, and it is even a matter of general belief among mariners, say MM. Quoy and Gaimard, that there occur in the equatorial seas shoals composed of corals, which rise from the greatest depths, like walls at the bottom of which the sounding line finds no ground. The fact certainly does exist in so far as regards the depth spoken of; and it is this very circumstance which is productive of so much danger to vessels, which, when taken in a calm and carried away by currents, cannot cast anchor in such places. But it is not correct to say that these reefs are entirety formed of madrepores. First, because the species which always form the most considerable banks, such as some meandrinÆ, certain caryophylleÆ, but especially the astreÆ, adorned with the most beautiful and velvety colours, require the influence of light to perfect them; because they are not seen to grow beyond a few yards of depth; and because they cannot consequently be developed at a depth of ten or twelve hundred feet, as they would necessarily be, did they raise the cliffs in question. Besides, these different species of animals would then almost exclusively enjoy the privilege of living at all depths, under all degrees of pressure, and, so to speak, in all temperatures.

Another circumstance to which navigators have not adverted, which corroborates the opinion here stated, is, that, in depths so great as those to which we allude, the sea, always agitated at the surface, breaks with force upon these reefs, without requiring for that purpose any additional impulse from the winds. And by merely attending to the necessary consequences of the observations of these same navigators, who say (what is very true) that, wherever the waves are agitated, the lithophytes are unable to go on with their work, because they destroy their frail edifices, we shall acquire the moral certainty that these submarine steeps are not produced by these animalcules. But, in these same places, let there occur a hollow, a sheltered spot of some kind, and then they will immediately raise their habitations, and will contribute to diminish the little depth that already exists there. And this is what may be seen in almost all the places where an elevated temperature permits these animals to grow in abundance.

In the localities where the tides are sensible, their currents alone may sometimes form irregular canals between the madrepores, without their ever being encumbered with their species, from the twofold cause united, of the motion and the coldness of the water; while, on the other hand, the flexible alcyonia are seen to multiply there.

When these geological dispositions are carefully observed, we see that the zoophytes rise to the surface of the waves, never beyond it; after which the generation which has attained thus far appears to die. It is destroyed much sooner, if, from the effect of the tides, these frail animalcules are exposed naked to the action of a burning sun. When there occur small hollows in these heaps of inert spoils, deprived of their inhabitants, which are always covered by the water, several tufts of those lithophytes are still remarked, which, having escaped from the almost general destruction, glow with the most lively colours. Then, the families which are developed anew, not being able to build on the outside of those reefs on which the sea is constantly breaking, draw nearer and nearer the shore, where the waves now deadened have scarcely any more action upon them, as in the Isle of France, at Timor, the Papua, the Marian, and the Sandwich Islands; provided always the waters had not a great depth, as is the case at Turtle Island, of which Cook speaks, where no bottom is found between the madrepore reefs and the island, notwithstanding the shortness of the space which exists between these two points.

If we examine these animals in the places best adapted to their growth, we shall see their different species, the forms of which, as varied as they are elegant, become rounded into balls, spread out into fans, or ramify into trees, mingling together, blending with each other, and reflecting the varied hues of red, yellow, blue and violet.

It is well known that all these alleged walls, exclusively formed of corals, are intersected with openings through which the sea enters and retires with violence; and every body knows the danger which Captain Cook ran on one occasion, on the coast of New Holland, when he had no other resource, in order to save himself from destruction, than to take the sudden resolution of attempting one of these narrow passes, where one is always sure of finding plenty of water. And this circumstance also comes in support of what we have advanced; for, if these perpendicular walls were entirely composed of madrepores, they would present no deep openings in their continuity, because it is the property of zoophytes to build in masses that have no interruption; and because, again, could they raise themselves from very great depths, they would end with encumbering and shutting up these passages; a circumstance which does not take place, and probably never will, from the causes which we have related.

If these facts prove, that madrepores cannot exist at very great depths, the submarine rocks, which they only increase in height, are not, therefore, exclusively formed by them.

We now come to the second part of the argument; and we assert, that there are no islands of any magnitude and constantly inhabited by man, that are formed by corals; and that the layers which they construct under the water, are not more than a few fathoms in thickness.

We shall commence with the second part of this question. The impossibility of penetrating to the bottom of the sea to examine at what precise depth the solid zoophytes establish themselves, constrains us to confine ourselves to what has taken place in former times; and the monuments which the ancient revolutions of the globe have disclosed to our view, will serve to prove what is going on in our own days. We shall mention what has been seen in several places, and we shall first speak of the island which Peron took for the theatre of the great works of these polypi, namely the island of Timor.

The banks of coral which the sea has left exposed in the land, as it retired, are remarkable for their uncommon magnitude. The whole shores of Coupang are formed of them, and the low hills in its vicinity are enveloped in them; but a few hundred yards from the town, they disappear, when distinct strata of slate make their appearance. The corals form a bed over the subjacent rocks from 25 to 80 feet thick.

Every thing announces that, in the Island of Timor, there exist no mountains exclusively formed of corals. As in all extensive countries, they are composed of various substances. Quoy and Gaimard having coasted it for about fifty leagues, sufficiently near to enable them to form an idea of its geography, were able to see that it exhibited volcanic appearances in several parts. Besides it abounds in mines of gold and copper, which, in conjunction with what we have already mentioned, shews in a general way the nature of the rocks of which it is composed.

Perhaps, remarks Quoy and Gaimard, the Bald-Head, a mountain of King George’s harbour in New Holland, which Vancouver has described in passing, and on the summit of which he saw perfectly preserved branches of coral, might be adduced as a fact in opposition to the opinion here advanced. Yet the phenomenon exhibited there, is still precisely the same as at Timor, and in a thousand other places[382]. The zoophytes have built upon a basis previously existing, and they occupy only the surface of it. For why should this Bald-Head differ from Mount Gardner, which, although close by it, is formed of primitive rocks? Besides, Peron says, that it has the same geological constitution. (T. ii. p. 133.)

At Rota, one of the Marian Isles, M. Gaudichaud, detached from the limestone rock, at about a hundred toises above the level of the sea, branches of true madrepores, in perfect preservation. Here are, then, three localities in which they are found at great heights. We have observed them, say the French naturalists, at infinitely lower elevations in several other places, as at the Isle of France, where they form a bed more than six feet thick, between two streams of lava; at Wahou, one of the Sandwich Islands, where they have not a greater elevation, but extend for several hundred toises over the surface of the island. In all these cases, it is necessary to distinguish between the lithophytes, which have, by their living powers, formed continuous masses, from those which, after having been rolled about, broken down by the water, and mixed with sea shells, contribute to form those deposits known by the name of madrepore limestone. The latter sort is nothing but the debris of the former. Deposits of this description occur in the Marian Isles, and in those of the Papous; they occur also on the coasts of France, and in several other places.

It would appear from observations made in Timor and other places, that the species of the genus AstrÆa which are the only ones capable of covering immense extents of surface, do not commence their operations at a greater depth than twenty-five or thirty feet, in order to raise their habitations to near the surface of the sea. Fragments of these species are never obtained, either with the sounding line, or upon the anchors; nor do we ever see them, unless in places where the water is shallow; while the branched madrepores, which do not form thick and continuous beds, either on the elevated places which the ocean has left, or on the shores where they still exist, live at considerable depths.

It is evident, then, that these corals have erected their fabrics on the summits of submarine hills and mountains; and that all those reefs of Taiti, the Dangerous Archipelago, Navigators’ Islands, the Friendly Islands, &c. are composed of madrepores only at the surface.

We thus consider it demonstrated, that the rocks of the solid zoophytes or coral, are not capable of forming the immense bases on which the greater number of the islands that occur in the Pacific Ocean rest.

There now remains for us to state how these animals, by their union, are capable of raising small islets. Forster, as already stated, has given a very good description of the manner in which this is effected. In fact, when these animalcules have raised their habitations to the surface of the water, under the shelter of the land, and they remain uncovered during the reflux of the tide, the hurricanes which sometimes supervene, by the agitation which they produce in those shallow waters, throw up from the bottom sand and mud. These substances are detained in the sinuosities and cavities formed between the corals, and thus serve to fix them together, and connect them into masses. Whenever the summit of this new island can remain constantly uncovered by the sea, and the waves can no longer destroy what they themselves have contributed to form, then its extent is enlarged, and its edges are gradually raised by the successive addition of sand. According to the direction of the winds and currents they may long remain sterile; but if the seeds of vegetables be transported to them from the neighbouring shores, by the action of these two causes, then, in latitudes favourable to their development, we presently see these islands becoming covered with verdure, the successively accumulated remains of which form layers of soil, which contribute to the elevation of the surface.

But, in order that this phenomenon of growth be accomplished, the distance from land must not be too great, because then the vegetables cannot get so easily to the islets in question, which then remain almost always bare and sterile. And for this reason what navigators report of those madrepore Islands of the Great Ocean, which are covered with verdure, and are yet at a great distance from any known land, has always appeared to us extraordinary; and that so much the more, that, in those vast spaces, the violence of the waves, which nothing can break there, must disturb the operations of the zoophytes. We do not, however, deny the existence of these islands, which it would be interesting carefully to examine anew; for, whenever navigators meet with low islands between the Tropics, they do not hesitate, in compliance with the generally received opinion, to say that they consist of madrepores. Yet how many islands, which scarcely rise above the surface of the water, recognise no such origin? We may mention, as an example, the Island of Boni, situated under the equator, the beautiful vegetation of which rises upon limestone. Cocoa Island, near Guam, is in the same condition, being also composed of limestone. In general, if they are inhabited, consequently they have springs or lakes of fresh water, we may almost be certain that they are not composed of lithophytes, or are only so in part, because springs could not be formed in their porous substances. Some of the Caroline Isles are excessively low; we supposed them encrusted with madrepores; and as they have inhabitants there must be somewhere in them a soil favourable to the accumulation of fresh water[383].

In restraining the power of these animalcules, concludes Quoy and Gaimard, and in pointing out the limits which nature has prescribed them, we have no other object than to furnish more correct data to the naturalists who aspire to great hypothetical considerations, regarding the conformation of the globe. On reconsidering these zoophytes with greater attention, they will no longer be seen filling up the basins of the seas, raising islands, increasing the size of the continents, threatening future generations with a solid equatorial circle formed of their spoils. Their influence, with regard to the road-steads or harbours, in which they multiply, is already great enough, without adding more to it. But, compared with the masses on which they rest, what are their layers, often interrupted, and which must be searched for with care, before they can be recognised, to the enormous volcanic peaks of the Sandwich Islands, the Island of Bourbon, the Moluccas, the Marian Islands, the mountains of Timor, New Guinea, &c. &c.? Nothing, certainly; and the solid zoophytes are in no degree capable of being compared with the testaceous mollusca, with reference to the materials which they have furnished, and still continue to furnish to the crust of the Globe.

Note I, p. 33.

ON THE LEVEL OF THE BALTIC.

About the middle of the last century, a controversy took place among the natural philosophers of the north of Europe, regarding the alleged gradual lowering of the level of the sea in general, and of the Baltic Sea in particular. Celsius was the first who introduced this idea to notice. He generalised it by applying it to all the planets, and was supported by the authority of the celebrated LinnÆus. He soon perceived, however, that the point could never be settled by mere discussion, and that facts alone could lead to any certain result. Observation was therefore had recourse to; and thus the dispute in question had at least one good effect, that of directing to the subject the attention of men of science, whose situation might enable them to mark the variations of level that take place along the coasts of the North Sea. The results of investigations undertaken for this purpose, are now beginning to be collected.

In the course of 1820 and 1821, Mr Bruncrona, assisted by the officers of the Pilotage Establishment, and other qualified persons, undertook the examination of all the authentic measures that had been established upon the west coast of the Baltic, during the last half century. The results of this examination are given in a short memoir, inserted in the Swedish Transactions for 1823. The following table indicates the degree to which the level of the sea has fallen during the last forty years, on the coast of Sweden, at various latitudes. It is proper to remark, that, in some of the places observed, the measures were much older, and in some others much more recent, than the period of forty years. In both these cases, the change of level that must have been effected during this period, has been estimated, by calculating the mean annual depression furnished by the observations.

Latitude. Fall of surface
in forty years.
Latitude. Fall of surface
in forty years.
Latitude. Fall of surface
in forty years.
East Coast. Feet. East Coast. Feet. East Coast. Feet.
63° 59' 1.50 59° 17' 2.17 56° 10' 0.00
... ... 2.50 58 44 1.00 56 11 0.00
... ... 0.50 58 42 1.08 55 53 0.00
61 43 2.50 58 45 1.17
61 37 2.83 58 35 2.00 South-West Coast.
61 32 2.50 58 28 0.07 55 23 0.00
61 45 2.50 58 11 0.83 55 22 0.00
60 11 2.33 58 8 1.00 57 21 0.00
59 46 0.17 57 50 1.00 57 53 1.00
59 46 2.00 56 41 0.41

Of the facts collected in the course of this investigation, the following may be mentioned as tending to support the opinion of a fall of level.

1st, It is generally believed among the pilots of the Baltic, that the sea has become shallower along the course which vessels ordinarily follow; but, it is added, that this alteration is more sensible in the places where the tide collects sand, detached pebbles, and sea-weeds, or in those where the bottom is composed of rocks. The same observation has been made in the neighbourhood of some large towns and fisheries; for example, a hydrographic chart made in 1771, gives six fathoms for the mean depth of the sea opposite the harbour of Landskrona, whereas, in 1817, the sounding line scarcely gave five fathoms at the same point.

2d, According to the oldest and most experienced pilots, the straits which separate the numerous islets scattered along the coast of Sweden, from Haarparanda to the frontiers of Norway, received vessels that drew ten feet of water; now they are not practicable for boats that draw more than two or three feet.

3d, The pilots further affirm, that, along the whole coast of Bahusia, the bottom undergoes a diminution, which becomes sensible every ten years in certain places, where it is composed of rocks. Several other parts of the Baltic may be cited, in which a similar change has been remarked.

M. C. P. Hallstrom, in an Appendix to Mr Bruncrona’s Memoir, gives the following table of the diminution observed in the depth of the waters of the Gulf of Bothnia.

Places. Mean marked
in
Height
of the water
reobserved
in
Fall beneath
the original
mark in feet.
Number
of years.
Fall of the
water in 100
years, in feet.
Raholem, parish of Lower Kalix, 1700 1750 2.05 50 4.10
1775 2.49 75 4.32
Stor Rebben, parish of Pitea, 1751 1785 1.70 34 5.00
1796 1.90 45 4.22
Ratan, parish of Bygdea, 1749 1785 2.70 36 4.72
1795 2.50 46 5.43
1819 2.60 70 3.47
1774 1785 0.55 11 5.00
1795 1.16 21 5.52
1819 1.60 45 3.57
1795 1819 0.65 24 2.71
RÖnnskat, on the coast of Wasa, 1755 1797 1.70 42 4.05
1821 2.87 65 4.35
WargÖn, on the coast of Wasa, 1755 1785 1.45 30 4.83
1797 1.69 42 4.02
1821 2.87 65 4.35
LÖgfrundet, near Sefle, 1731 1785 2.90 54 5.37
1796 2.17 65 3.34
Ulfon, in Angermanland, 1795 1822 1.58 27 5.85

It is not demonstrated that the numbers of the last column represent exactly the lowering of the water in a century; for it has not yet been sufficiently determined if this lowering be uniform, or if it vary at different periods, and if it depend upon some local circumstance,—upon the climate,—or upon the state of the atmosphere. Nor is it properly established, that this lowering, which becomes less perceptible from the north of the Baltic, until it disappears entirely at the southern extremity, follows precisely the same law of diminution as the latitude. It appears to be uniform in the whole extent of the Gulf of Bothnia, and it rises about four feet and a quarter in that region; at Calmar (lat. 57° 50') it is only two feet; but it is not yet known whether it decreases in a regular manner between these two places.

Some authors consider the facts related by MM. Bruncrona and Halstrom, as deciding the question in favour of those who believe in a lowering of the level of the Baltic. The editor of the Annalen der Physik[384] goes farther, and seems to consider it as confirming the opinion of a general lowering of the level of the sea. In support of this opinion, he adduces the traditions and observations of the natives of Otaheite and of the Moluccas and Sunda Islands, regarding the retreat of the sea in several parts of their coast. We are disposed to stand neutral in this matter. The geographers who have collected the greatest number of facts relating to the level of the inland seas, and of the ocean in its various regions, find nearly as many in favour of a rise as in favour of a fall of level. The very distribution of contrary indications, leads them to believe in a partial displacement of the mass of waters from one region towards another, and even from the one side of an inland sea towards the opposite side; a displacement which might be owing to fugitive or more or less durable causes, such as a variation of temperature in the polar regions, the action of winds and of currents, modified by the greater or less quantity of water in the rivers that feed the different basins, upon the sides opposed to their direction.

Are the facts contained in the memoir in question of a nature to overthrow this opinion? They do not appear so to us. The two series of observations which are adduced, only shew a fall upon the coasts of Sweden, properly so called, that is to say, upon the west coast of the Baltic, and the east coast of the Cattegat. Two observations only have been made upon the coasts of Finland, toward the extremity of the Gulf of Bothnia. These facts would perfectly accord with the opinion of those who think that the currents determined from the north to the south of the Baltic by the numerous streams which rush into it, push the waters toward the south shore, that of Pomerania, Mecklenbourg, and Holstein; and that the waters consequently gain upon the land on this coast, as numerous historical facts attest, while they retire along the northern shores, those of the Gulf of Bothnia. Be this as it may, the question as to the constancy of the level of the sea cannot be considered as decided, until a long series of observations shall have been made upon authentic and perfectly fixed measures erected upon all the shores of the different seas, and of the different regions of the ocean. Those which have been published in the Swedish Transactions furnish important documents for this purpose; and similar ones should be begun to be collected in other countries.

The phenomena exhibited by the waters of the Baltic engaged the attention of two rival speculators, Playfair and Deluc; and their views are often alluded to by geologists. We shall here state them in their own words. Professor Playfair, in his well known and elegant work on the Huttonian Theory of the Earth, has the following remarks:

“If we proceed further to the north, to the shores of the Baltic for instance, we have undoubted evidence of a change of level in the same direction as on our own shores. The level of the sea has been represented as lowering at so great a rate as forty inches in a century. Celsius observed, that several rocks which are now above the water, were not long ago sunken rocks, and dangerous to navigators; and he took particular notice of one which, in the year 1680, was on the surface of the water, and, in the year 1731, was 20½ Swedish inches above it. From an inscription near Aspo, in the lake Melar, which communicates with the Baltic, engraved, as is supposed, about five centuries ago, the level of the sea appears to have sunk in that time no less than thirteen Swedish feet. All these facts, with many more which it is unnecessary to enumerate, make the gradual depression, not only of the Baltic, but of the whole Northern Ocean, a matter of certainty.”—Playfair’s Illustrations, p. 445.

That indefatigable and accurate observer De Luc, has the following commentary on the preceding passage.

“It would be unnecessary to mention even the two inconsiderable facts above, if the depression of the level of the seas were indeed a matter of certainty; for the best authenticated and the least equivocal monuments of their change would then abound along all their coasts. But proofs are every where found that such a change is chimerical: they may be seen in all the vales coming down to these seas, in which there is no perceptible impression of the action of any waters but those of the land, and no vestige, through their whole extent, of any permanent abode of those of the sea; and proofs to the same effect are equally visible, along the coasts of both these seas, in all the new lands which have been formed on them, and which, being perfectly horizontal from the point where their formation commenced, evidently show that the water displaced by them has been constantly at the same level. Hence appears the necessity of multiplying, as I have done, and shall continue to do, for the subversion of a prejudice of such ancient date, the examples of these peremptory proofs of its total want of foundation. The rock mentioned by Celsius had probably been observed by him at times when the level of the sea was different; its known differences much exceeding the quantity here specified. As for the inscription near Aspo, in a country abounding with lakes as much as that which I have above described, if we are acquainted with its terms, we should probably find it to be, like many which I have seen in various places along the course of the Oder and the Elbe, the monument of some extraordinary inundation of the land, from the sudden melting of the snows in the mountains, at a time when the water had been prevented from running off by an equally extraordinary rise of the level of the sea; of which the effects on low coasts may extend very far inland.

“By this conclusion, however, from these few facts, contrary to every thing observed on the coasts of this sea, Mr Playfair thinks himself authorised to maintain, that the gradual depression, not only of the Baltic, but of the whole northern ocean, is a matter of certainty; afterwards he examines merely which of these two causes, the subsidence of the sea itself, or the elevation of the land around it, agrees the best with the phenomena; and he decides in favour of the latter, pointing out its accordance with the Huttonian Theory.”

Note L, p. 119.

FOSSIL REMAINS OF THE HUMAN SPECIES.

From the observations of Werner and others, it appears, that the most simple animals are those first met with in a mineralized state; that these are succeeded by others more perfect, and which are contained in newer formations; and that the most perfect, as quadrupeds, occur only in the newest formation. But we naturally inquire, have no remains of the human species been hitherto discovered in any of the formations? Judging from the arrangement already mentioned, we would naturally expect to meet with remains of man in the newest of the formations. In the writings of ancient authors there are descriptions of anthropolithi. In the year 1577, Fel. Plater, Professor of Anatomy at Basle, described several fossil bones of the elephant found at Lucerne, as those of a giant at least nineteen feet high. The Lucernese were so perfectly satisfied with this discovery, that they caused a painting to be made of the giant, as he must have appeared when alive, assumed two such giants as the supporters of the city arms, and had the painting hung in their public hall. The Landvoigt Engel, not satisfied with this account of these remains, maintained that our planet, before the creation of the present race of men, was inhabited by fallen angels, and that these bones were part of the skeletons of some of those miserable beings. Scheuchzer published an engraving and description of a fossil human skeleton, which proved to be a gigantic species of salamander or proteus. Spallanzani describes a hill of fossil human bones in the island of Cerigo; but this also is an error, as has been satisfactorily shewn by Blumenbach. Lately, however, a fossil human skeleton has been imported into this country from Guadaloupe, by Sir Alexander Cochrane. It is imbedded in a block of calcareous stone, composed of particles of limestone and coral, and which, like the aggregations of shells found on the limestone coasts in some parts of this country, has acquired a great degree of hardness. It is therefore an instance of a fossil human petrifaction in an alluvial formation. The engraving here given is copied from the Philosophical Transactions of the Royal Society of London; and the following description of the fossil remains it exhibits is that of Mr Konig, which has been drawn up with great care.

“The situation of the skeleton in the block was so superficial, that its presence in the rock on the coast had probably been indicated by the projection of some of the more elevated parts of the left fore-arm.

“The operation of laying the bones open to view, and of reducing the superfluous length of the block at its extremities, being performed with all the care which its excessive hardness, and the relative softness of the bones, required, the skeleton exhibited itself in the manner represented in the annexed drawing (Pl. I.) with which my friend Mr Alexander has been so good as to illustrate this description.

“The skull is wanting; a circumstance which is the more to be regretted, as this characteristic part might possibly have thrown some light on the subject under consideration, or would, at least, have settled the question, whether the skeleton is that of a Carib, who used to give the frontal bone of the head a particular shape by compression, which had the effect of depressing the upper and protruding the lower edge of the orbits, so as to make the direction of their opening nearly upwards, or horizontal, instead of vertical[385].

“The vertebrÆ of the neck were lost with the head. The bones of the thorax bear all the marks of considerable concussion, and are completely dislocated. The seven true ribs of the left side, though their heads are not in connexion with the vertebrÆ, are complete; but only three of the false ribs are observable. On the right side only fragments of these bones are seen; but the upper part of the seven true ribs of this side are found on the left, and might at first sight be taken for the termination of the left ribs; as may be seen in the drawing. The right ribs must therefore have been violently broken and carried over to the left side, where, if this mode of viewing the subject be correct, the sternum must likewise lie concealed below the termination of the ribs. The small bone dependent above the upper ribs of the left side, appears to be the right clavicle. The right os humeri is lost; of the left nothing remains except the condyles in connexion with the fore-arm, which is in the state of pronation; the radius of this side exists nearly in its full length, while of the ulna the lower part only remains, which is considerably pushed upwards. Of the two bones of the right fore-arm, the inferior terminations are seen. Both the rows of the bones of the wrists are lost, but the whole metacarpus of the left hand is displayed, together with part of the bones of the fingers: the first joint of the fore-finger rests on the upper ridge of the os pubis; the two others, detached from their metacarpal bones, are propelled downwards, and situated at the inner side of the femur, and below the foramen magnum ischii of this side. Vestiges of three of the fingers of the right hand are likewise visible, considerably below the lower portion of the fore-arm, and close to the upper extremity of the femur. The vertebrÆ may be traced along the whole length of the column, but are in no part of it well defined. Of the os sacrum, the superior portion only is distinct: it is disunited from the last vertebra and the ilium, and driven upwards. The left os ilium is nearly complete, but shattered, and one of the fragments depressed below the level of the rest; the ossa pubis, though well defined, are gradually lost in the mass of the stone. On the right side, the os innominatum is completely shattered, and the fragments are sunk: but towards the acetabulum, part of its internal cellular structure is discernible.

“The thigh-bones, and the bones of the leg of the right side, are in good preservation, but being considerably turned outwards, the fibula lies buried in the stone, and is not seen. The lower part of the femur of this side is indicated only by a bony outline, and appears to have been distended by the compact limestone that fills the cavities both of the bones of the leg and thigh, and to the expansion of which, these bones probably owe their present shattered condition. The lower end of the left thigh-bone appears to have been broken and lost in the operation of detaching the block; the two bones of the leg, however, on this side, are nearly complete; the tibia was split almost the whole of its length a little below the external edge, and the fissure being filled up with limestone, now presents itself as a dark-coloured straight line. The portion of the stone which contained part of the bones of the tarsus and metatarsus, was unfortunately broken; but the separate fragments are preserved.

“The whole of the bones, when first laid bare, had a mouldering appearance, and the hard surrounding stone could not be detached without frequently injuring their surface; but after an exposure for some days to the air, they acquired a considerable degree of hardness. Sir H. Davy, who subjected a small portion of them to chemical analysis, found that they contained part of their animal matter, and all their phosphate of lime.”

Note M, p. 128.

Account of the Displacement of that part of the Coast of the Adriatic which is occupied by the Mouths of the Po.

That portion of the shore of the Adriatic which lies between the lake, or rather lagune, of Commachio, and the lagunes of Venice, has undergone considerable alterations since ancient times, as is attested by authors worthy of entire credit, and as is still evinced by the actual state of the soil in the districts near the coast; but it is impossible now to give any exact detail of the successive progress of these changes, and more especially of their precise measures during the ages which preceded the twelfth century of our era.

We are, however, certain, that the city of Hatria, now called Adria, was formerly situated on the edge of the coast; and by this we attain a known fixed point upon the primitive shore, whence the nearest part of the present coast, at the mouth of the Adige, is at the distance of 25,000 metres[386]; and it will be seen in the sequel, that the extreme point of the alluvial promontory formed by the Po, is farther advanced into the sea than the mouth of the Adige by nearly 10,000 metres[387].

The inhabitants of Adria have formed exaggerated pretensions, in many respects, as to the high antiquity of their city, though it is undeniably one of the most ancient in Italy, as it gave name to the sea which once washed its walls. By some researches made in its interior and its environs, a stratum of earth has been found mixed with fragments of Etruscan pottery, and with nothing whatever of Roman manufacture. Etruscan and Roman pottery are found mixed together in a superior bed, on the top of which the vestiges of a theatre have been discovered. Both of these beds are far below the level of the present soil. I have seen at Adria very curious collections, in which these remains of antiquity are separately classed; and having, some years ago, observed to the viceroy, that it would be of great importance, both to history and geology, to make a thorough search into these buried remains at Adria, carefully noticing the levels in comparison with the sea, both of the primitive soil, and of the successive alluvial beds, his Highness entered warmly into my ideas; but I know not whether these propositions have been since carried into effect.

Following the coast, after leaving Hatria, which was situated at the bottom of a small bay or gulf, we find to the south a branch of the Athesis or Adige, and of the Fossa Philistina, of which the remaining trace corresponds to what might have been the Mincio and Tartaro united, if the Po had still run to the south of Ferrara. We next find the Delta Venetum, which seems to have occupied the place where the lake or lagune of Commachio is now situated. This delta was traversed by seven branches of the Eridanus or Po, formerly called also the Vadis Padus or Podincus; which river, at the diramification of these seven branches, and upon its left or northern bank, had a city named Trigoboli, whose site could not be far from where Ferrara now stands. Seven lakes, inclosed within this delta, were called Septem Maria, and Hatria was sometimes denominated Urbs Septem Marium, or the city of the seven seas or lakes.

Following the coast from Hatria to the northwards, we come to the principal mouth of the Athesis or Adige, formerly named Fossa Philistina, and afterwards Estuarium Altini, an interior sea, separated by a range of small islands from the Adriatic Gulf, in the middle of which was a cluster of other small isles, called Rialtum, and upon this archipelago the city of Venice is now seated. The Estuarium Altini is what is now called the Lagune of Venice, and no longer communicates with the sea, except by five passages, the small islands of the Archipelago having been united into a continuous dike.

To the east of the lagunes, and north from the city of Este, we find the Euganian mountains, or hills, forming, in the midst of a vast alluvial plain, a remarkable isolated group of rounded hills, near which spot the fable of the ancients supposes the fall of PhÆton to have taken place. Some writers have supposed that this fable may have originated from the fall of some vast masses of inflamed matters near the mouths of the Eridanus, that had been thrown up by a volcanic explosion; and it is certain that abundance of volcanic products are found in the neighbourhood of Padua and Verona.

The most ancient notices that I have been able to procure respecting the situation of the shores of the Adriatic at the mouths of the Po, only begin to be precise in the twelfth century. At that epoch the whole waters of this river flowed to the south of Ferrara, in the Po de Volano and the Po di Primaro, branches which inclosed the space occupied by the lagune of Commachio. The two branches which were next formed by an irruption of the waters of the Po to the north of Ferraro, were named the river of Corbola, Longola, or Mazzorno, and the river Toi. The former, and more northern of these, received the Tartaro, or canal bianco, near the sea, and the latter was joined at Ariano by another branch derived from the Po, called the Goro river. The sea-coast was evidently directed from south to north, at the distance of ten or eleven thousand metres[388] from the meridian of Adria; and Loreo, to the north of Mesola, was only about 2000 metres[389] from the coast.

Towards the middle of the twelfth century, the flood-waters of the Po were retained on their left or northern side by dikes near the small city of Ficarolo, which is about 19,000 metres[390] to the north-west of Ferrara, spreading themselves southwards over the northern part of the territory of Ferrara and the Polesine of Rovigo, and flowed through the two formerly mentioned canals of Mazzorno and Toi. It seems perfectly ascertained, that this change in the direction of the waters of the Po had been produced by the effects of human labours; and the historians who have recorded this remarkable fact only differ from each other in some of the more minute details. The tendency of the river to flow in the new channels, which had been opened for the more ready discharge of its waters when in flood, continually increased; owing to which the two ancient chief branches, the Volano and Primaro, rapidly decreased, and were reduced in less than a century to their present comparatively insignificant size; while the main direction of the river was established between the mouth of the Adige to the north, and what is now called Porto di Goro, on the south. The two before-mentioned canals of Mazzorno and Toi becoming insufficient for the discharge, others were dug; and the principal mouth, called Bocco Tramontana, or the northern mouth, having approached the mouth of the Adige, the Venetians became alarmed in 1604; when they excavated a new canal of discharge, named Taglio de Porto Viro, or Po delle Fornaci, by which means the Bocco Maestra, was diverted from the Adige towards the south.

During four centuries, from the end of the twelfth to that of the sixteenth, the alluvial formations of the Po gained considerably upon the sea. The northern mouth, which had usurped the situation of the Mazzorno canal, becoming the Rama di Trimontana, had advanced in 1600 to the distance of 20,000 metres[391] from the meridian of Adria; and the southern mouth, which had taken possession of the canal of Toi, was then 17,000 metres[392] advanced beyond the same point. Thus the shore had become extended nine or ten thousand metres[393] to the north, and six or seven thousand to the south[394]. Between these two mouths there was formerly a bay, or a part of the coast less advanced than the rest, called Sacca di Goro. During the same period of four hundred years previous to the commencement of the seventeenth century, the great and extensive embankments of the Po were constructed; and also, during the same period, the southern slopes of the Alps began to be cleared and cultivated.

The great canal, denominated Taglio di Porto Viro, or Po delle Fornaci, ascertains the advance of the alluvial depositions in the vast promontory now formed by the mouths or delta of the Po. In proportion as their entrances into the sea extend from the original land, the yearly quantity of alluvial depositions increases in an alarming degree, owing to the diminished slope of the streams, which was a necessary consequence, of the prolongation of their bed, to the confinement of the waters between dikes, and to the facility with which the increased cultivation of the ground enabled the mountain torrents which flowed into them to carry away the soil. Owing to these causes, the bay called Sacra di Goro was very soon filled up, and the two promontories which had been formed by the two former principal mouths of Mazzorno and Toi, were united into one vast projecting cape, the most advanced point of which is now 32,000 or 33,000 metres[395] beyond the meridian of Adria: so that in the course of two hundred years, the mouths or delta of the Po have gained about 14,000 metres[396] upon the sea.

From all these facts, of which I have given a brief enumeration, the following results are clearly established.

First, That, at some ancient period, the precise date of which cannot be now ascertained, the waves of the Adriatic washed the walls of Adria.

Secondly, That, in the twelfth century, before a passage had been opened for the waters of the Po at Ficarrolo; on its left or northern bank, the shore had been already removed to the distance of nine or ten thousand metres[397] from Adria.

Thirdly, That the extremities of the promontories formed by the two principal branches of the Po, before the excavation of the Taglio di Porto Viro, had extended, by the year 1600, or in four hundred years, to a medium distance of 18,500 metres[398] beyond Adria; giving, from the year 1200, an average yearly increase of the alluvial land of 25 metres[399].

Fourthly, That the extreme point of the present single promontory, formed by the alluvions of the existing branches, is advanced to between thirty-two and thirty-three thousand metres[400] beyond Adria; whence the average yearly progress is about seventy metres[401] during the last two hundred years, being a greatly more rapid proportion than in former times.

Prony.

Note, p. 244.

On the Universal Deluge.

Mr Cuvier in the present work, and more recently in a note to Mr Lemaire’s edition of Ovid’s Metamorphoses, enumerates the Mosaic, Grecian, Assyrian, Persian, Indian, and Chinese traditions, concerning a universal deluge; and concludes from them, that the surface of the globe, five or six thousand years ago, underwent a general and sudden revolution, by which the lands inhabited by the human beings who lived at that time, and by the various species of animals known at the present day, were overflowed by the ocean; out of which emerged the present habitable portions of the globe. This celebrated naturalist maintains, that these regions of the earth were peopled by the few individuals who were preserved, and that the tradition of the catastrophe has been preserved among these new races of people, variously modified by the difference of their situation and their social disposition. According to Mr Cuvier, similar revolutions of nature had taken place, at periods long antecedent to that of the Mosaic deluge. The dry land was inhabited, if not by human beings, at least by land animals at an earlier period; and must have been changed from the dry land to the bed of the ocean; and it might even be concluded from the various species of animals contained in it, that this change, as well as its opposite, had occurred more than once.

This opinion being brought forward in a geognostic work, especially in a work abounding in such valuable matters of fact, and stated as the result of geognostic investigation, we may be permitted, in this point of view, to examine it; and to ask, whether, from the phenomena exhibited by the present condition of the earth’s surface, we are entitled to conclude that it owes its conformation to such a universal deluge.

We know, from arguments suggested by chemistry and the higher mechanics, that the globe was once in a state of fluidity; hence it might be maintained with some appearance of probability, that the condition of the earth, previous to the existence of organic matter, depended upon fusion; and that the primitive rocks are of igneous origin. Since, however, granite has been found above rocks of various kinds which contain the remains of organic bodies, we are under no necessity of ascribing to primitive rocks an origin different from that of subsequent formations; and, without having recourse to other arguments, the fact, that aquatic animals are the most abundant of fossil organic remains from the earliest of the transition to the latest of the secondary and tertiary formations, affords evidence that they are precipitates from water.

Notwithstanding the great and daily advancement of science, our knowledge of chemistry is still too imperfect for us to arrive at an adequate knowledge of the state of this water, or rather sea, as, from its universal expansion, it must be denominated. Did it contain dissolved in it at the same time all the materials from which the various beds of rock were formed; what were the solvents of those materials which we find, either insoluble in water, or at least not easily soluble; by what means were the precipitates produced; and whence came this prodigious mass of waters? Upon these unanswered questions depend others no less important. The aquatic animals of a former world undoubtedly lived in this sea; otherwise, we must admit of another sea free from heterogeneous materials. But did these animals continue to live in it during the whole process of precipitation; and did this process proceed so slowly and imperceptibly, that animal life was not interrupted by it, and that only remains of dead animals, such as the skeletons of fishes, and the covering of shell-fishes, were enveloped in the precipitates? Or, did animal life continue only during the state of solution; and were the myriads of aquatic animals found in beds of rocks buried in them alive? Many naturalists appear to entertain the latter opinion, from observing the agonies of death depicted in the distorted position of fishes in copper-slate, or from deriving the bituminous properties of stink-stone, as well as of marl, from the decomposition of animal bodies, of which such numerous vestiges are extant in these beds? In this way a plausible explanation is given of the phenomena of a former world that has perished. How, then, do they explain the constant appearance of so many species, which have continued without interruption for such an infinite length of time? Have these species been propagated by individuals who accidentally escaped destruction: or, Does a new race continually spring up again? But laying aside the difficulty of this explanation, the violent destruction of so many races of animals, is scarcely consistent with the general order of the universe, according to which, we behold every animal occupying its proper element, and fulfilling its particular destiny. We, therefore, involuntarily revert to the opinion, that those creatures, whose remains are preserved in beds of rocks, have lived continually in the sea, out of which the rocks were precipitated, in the same manner as the analogous species now living in the sea become enveloped in deposits still taking place, although on a comparatively small scale.

What has just been said does not entitle us to admit that the various parts of the earth have been, from time to time, overflowed with water. Yet are there other appearances which completely indicate such a change, namely, beds of coal, and the fossil remains of land animals. The carbonisation of roots of trees in clefts of rocks, and of marsh plants in peat-bogs, which takes place, as it were, under our own immediate observation; the transitions of bituminous wood into pitch-coal, the frequent presence of vegetables partly converted into coal, in the neighbourhood of beds of coal, and which are more abundant the nearer they are to these beds; and, finally, the chemical nature of coal, which is similar to that of vegetables, go to prove the vegetable origin of the older and independent coal formation.

Though some fossil vegetables might derive their origin, by being floated to quarters more or less remote from their native soil, as we find to be the case in many islands of the South Sea, and on other shores; on the other hand, neither the breadth and extent of beds of coal, nor the erect position in which fossil trees and reed plants are not unfrequently found in their neighbourhood, coincide with such an explanation. The plants, from which these beds were formed, once stood and grew in the place where they were buried; and, from these remains, we infer that they were entirely land plants, tree-ferns, Lycopodia, and other cryptogamia. It also appears undeniable, that the land, being once dry, was, during a longer or shorter time, covered with luxuriant vegetation; that it was afterwards overflowed with water, and then became dry land again. But, was this overflow of water produced by a sudden, violent, and universal catastrophe, such as we consider the deluge? Many circumstances leave room for opposite conjecture. If it is probable that the older or black coal is of vegetable origin, the plants from which it has originated, must have suffered an incomparably greater change than those of more recent coal formations. Their composition and their texture, afford evidence of a long operation of the fluid in which the changes were produced; and their situation, proves that the substance of the plants, though not entirely dissolved, was yet much comminuted, and was kept floating and swimming, and then precipitated. How can we, in any other way, account for the layers of sandstone and slate-clay, with which coal regularly alternates, so that from one to sixty alternate beds have been enumerated? How can we explain the combination of mineral coal with slate-clay, or account for the appearance of bituminous shale, flinty slate, of iron-pyrites and iron-ore, in the midst of mineral coal itself? We do not, however, admit of a repeated uncovering and covering of the land with water, and of a renewal of vegetation for every particular bed of coal; far from it, for violent inundations exhibit very different phenomena. These formations, like pure mineral formations, bear the evident impress of a lengthened operation, and of gentle precipitations; and whoever still entertains doubts regarding this, may have them completely removed by the condition in which vegetable remains are frequently found in the coal formations, by the perfect preservation of the most delicately shaped fern leaves, by the upright position of stems, and by other appearances of a similar character. It is also an important objection against the universality of the cover of water, notwithstanding the wide extent of beds of coal, that they are sometimes accompanied with fossil remains of fresh-water shells, from which we are entitled to draw the conclusion, that they must have been deposited in inclosed basins of inland waters.

From the beds of coal found in various situations among Alpine limestone, as well as in other secondary formations, under similar circumstances, we are at liberty to maintain that they are not indebted for their origin to any universal and sudden revolution.

When we proceed to the second division of coal formations, to brown coal, or to lignite, the principal difference we discover is, that the change which the vegetables have undergone, having taken place at a time when the chemical power had lost much of its energy, was incomplete; and besides, we observe in the different brown coal formations the same repetition of single beds alternating with other beds of rocks, the mixture of different minerals, and not unfrequently of upright stems. Some appear to be derived from sea plants, and others from fresh-water plants; but the greater proportion from land plants. They, equally with the beds of black coal, give evidence of a new overflow of water, and the water plants themselves, which never thrive at a great depth, and which frequently appear under prodigious beds of rocks, must have experienced such a change. But that change was scarcely of the kind which we understand by a deluge, and the frequent repetition of deluges indicated, according to some, by the repeated beds of coal from the transition to the newest tertiary periods, is hardly credible. It may be maintained, with more certainty, of brown coal than of black coal, that they have been formed in land water, and hence in limited and isolated basins of water, since fresh-water animals are their constant attendants.

Although the beds of coal of our secondary formations appear to have originated in a similar way with other mineral formations, and not by violent catastrophes, it is otherwise with a part of those vegetable remains which are met with in alluvial land. Subterranean forests, whose circumference, in some instances, extends about 70 square leagues, partly in a state of good preservation, and partly more or less decomposed, afford satisfactory proof of deluges, and have undoubtedly been covered up with earth by a violent eruption of standing or running water. But these are local effects, similar to what take place in our own day, but on a larger scale.

There are abundant fossil remains of land animals, resembling those of water animals, found in such a state of preservation, that we cannot suppose them to have been brought hither from distant places, and by means of currents. Their appearing in beds of rocks, or generally in aqueous precipitates, proves that the soil they first inhabited, must have been dry land, afterwards overflowed with water.

The appearance of what are called fresh water shells, in alternate beds with marine animals, being sometimes observed in newer floetz rocks in great abundance, seems to indicate a reiterated retreat and return of the sea. But however meritorious the labours of naturalists, through whom attention has been directed to the subject, may be in other respects, we are nevertheless disposed to entertain doubts concerning their conclusions. In our own seas and ponds upon the coasts, we observe the same testaceous animals growing equally well in salt water, and in water nearly fresh; and, again, fresh water animals living in salt water[402]. By artificial means the inhabitants of the sea may be changed into inhabitants of fresh water; as fresh-water animals are, in their turn, converted into marine animals, so that, to decide concerning the proper element of each individual species is often matter of difficulty. Therefore, other circumstances besides that of containing salt must be taken into account. The occasional plenty, scarcity, or absolute want of food; the soil being sometimes sandy, slimy, or rocky; the depth, extent, agitation or tranquillity of the water; and, finally, the quality of the air contained in it, may be as instrumental in determining the habitation of these animals, as the materials which the water holds in solution. An excellent observer has indeed very lately shewn in a treatise, which supports the idea of fresh-water formations, that we possess no unerring character for distinguishing sea shell-fish from those of fresh water; but admitted, notwithstanding the transition above stated, we can draw a line of distinction between them, we must not forget that this investigation is neither regarding sea shell-fish now existing, nor of our present waters. We indeed draw our conclusion, and not without reason, from similar conformation, similar modes of existence. But one of two things must be; either that the shell-fish, whose remains are found in beds of rocks, lived in the water out of which these beds were precipitated, or the water in which they lived, was dislodged by other water containing the materials of the precipitations. In the first and more generally admitted case, the water was so different from the present water, whether salt or fresh, that we cannot infer from the inhabitants of the latter any thing concerning the inhabitants of the former; but we can confidently maintain, that a greater resemblance prevails between our sea and land water, than between either the one or the other, and that fluid which was inhabited by the shell-fish. In other respects, there remains no other difference between fresh and salt water formations, but that the bottom upon which the former is placed once contained land water; a fact worthy of observation: but the notion of enclosed basins, and of isolated formations originating in them, the way in which fresh water formations are supposed to have taken place, remained a long time unsatisfactory. Finally, we may be permitted to ask, upon what grounds they considered themselves entitled to ascribe to the former sea the continual possession of a portion of salt, while the salt precipitates appear only at particular intervals, and after long interruptions? If the sea occasionally contained a great, and sometimes a very small, quantity of salt, it might equally be at times altogether without it. And yet it deserves to be remembered, that the beds of rock, to which the salt formations are most nearly related, contain no petrifactions; that, therefore, the so-called marine animals are wanting in those periods during which we have any direct evidence of the presence of salt water.

There is, however, a geognostic fact, which, in preference to all others, has been cited in evidence of violent revolutions and deluges, that is, the appearance of conglomerates or of reproduced kinds of stone. Indeed, there might still be a wide field for investigation here, and more than one formation, which now passes for sandstone, might be acknowledged as an original and chemical production; without having occasion to go so far as Mr Gerhard does with greywacke,—that is, to consider them as immediate precipitates from the atmosphere. But still conglomerates sufficiently genuine, will remain from the transition period through all the subsequent formations, to serve as acknowledged monuments of destruction, as well as of the renovation of what was destroyed. These are the Codices rescripti, in the archives of the Earth, out of which, the antiquarian will one day decipher the almost obliterated traces of her former condition, as well as the history of her changes. Though these conglomerates deviate so much in their nature, and in the character of their origin, from chemical productions, they have yet among themselves this remarkable and common characteristic, that, with few exceptions, the older are much less varied in character, and more extensive in distribution, than the newer, and that, at length, the newest conglomerates become mere local appearances. But, in reference to the main question which engages our attention, we may conjecture that the beds of rocks from which the sea had never retreated, might be assailed by its floods and currents, and shattered to pieces, as happens even in our own time, and the fragments be again reunited into solid rocks, by means of the still remaining dissolved matter in the water. But of many conglomerates it is evident that they have been deposited on the dry land, in the same way as our gravels. Jupiter, who took counsel with himself, whether he would destroy the sinful world with fire or water, and at length decided for water[403], may not be so justly considered the author of these appearances, as Saturn, who devoured his children. Or, to be less metaphorical in our language, it may perhaps have been with the origin of conglomerates, as it is in our own day with the origin of fragments of rock and boulders, in which the rock being fractured in various places by the alternations of heat and cold, by the influence of air and atmospheric water, falls into pieces of greater or smaller magnitude, which are carried forward by the water, and gradually rounded in their progress, so that they assume a more perfectly globular shape the farther they are removed from their original situation. Therefore, as regards the foregoing enquiry, it is not an unimportant circumstance, that the long but continual rolling of the boulders during their rounding, appears to be much more efficacious than a rapid and violent impetus, and that, in this case, as in many other geognostic appearances, time rather than force is to be taken into account. Another circumstance, perhaps, corresponds with this, that the change produced by the weather, not only by the first disunion, but also by the progressive disintegration of the rocks, by the blunting of the edges and corners, by the diminution of the fragments, and generally in the origin of the boulders and fragments of rocks of every description, has just as much influence as the mechanical operation of the water; and that a great part of the land called Alluvial, generally owes its existence to this cause[404]. But if, upon farther consideration, the conglomerates appear to derive their origin in a similar way with rolled masses of gravel, they afford evidence, nevertheless, of the elevated station of the water in the neighbourhood, from which they had been before removed; for their conglomeration could take place only under water; and, with few exceptions, they occupy an incomparably greater elevation than any of the coal formations, or any of the beds of rocks which enclose the remains of land animals.

Geognosy certainly contains many facts, which cannot be explained, but by a change from dry land to the bottom of the sea, although our knowledge of them is still so imperfect, that we cannot hazard a probable conjecture respecting the numbers of these changes, whether they commence at the same or at different periods in the various quarters of the world, and whether they are local or universal. These changes appear neither sudden nor violent, such as we consider revolutions of the earth, but at all times proceed with silent and regular steps, and depend upon similar causes, concealed it is true from us, such as the universal retreat of the waters from their original height to the present bed of the ocean. We do not belong to those geologists who divert the world from its axis for the purpose of explaining the inequalities of its surface, at whose command the Earth sometimes opens her bosom to engulf the sea, and at other times the floodgates of Heaven are lifted up to pour down another ocean. He who reflects on the devastation caused by earthquakes, inundations and the fall of mountains, even though they are merely local appearances confined to particular quarters, cannot help putting the question to himself, how the order, regularity and connection exhibited by strata of rocks, could in any measure exist, if the same or similar accidents had happened throughout the whole world, and if mechanical power had operated with such energy, and to such an extent? All our knowledge of the structure of the earth, and of the existence of its inhabitants, declares rather a quiet uninterrupted and continually progressive advancement in its formation and development.

In the lapse of geological epochs, we observe a gradation of rock formations following one another, in which the latter, however remotely connected, still appear sufficiently similar to the earlier to indicate a common origin, till they at length terminate in simple formations, resembling those which are presently taking place. When the precipitates were exhausted, and the structure was completed, nay, even earlier, its destruction commenced; not that violent destruction by which lofty mountains are torn asunder and levelled, no uproar of nature, no gigantic struggle of the elements, such as we commonly conceive, but a decomposition of the strata of rocks to a greater or less depth, caused partly by chemical, partly by mechanical, but slow operating powers, what they wanted in intensity being compensated by the endurance of their operation. According to the common law of nature, deficiency of power is supplied by duration of time; for, of all the oracles which have been consulted concerning the formation of the earth, there is no one which can make such important revelations to us as the oracle of the age of mountains. These operations at the earth’s surface generally appear to have produced its present figure, and to have designed it for the habitation of numerous organic beings. This appears as early as a suitable element occurred; first, in water, then in land animals; and, like the formation of rocks, we observe a regular succession of organic formations, the later always descending from the earlier, down to the present inhabitants of the earth, and to the last created being who was to exercise dominion over them. But here occurs this important distinction: the organic world with youthful vigour renews itself daily, and decomposes its materials only to reunite them by fresh combinations in uninterrupted succession; while the powers of the inorganic world appear almost extinguished. Though this course of nature is manifest to our own observation, her resources and progress are, on the contrary, more concealed; and we can hardly lift the veil which conceals her, unless we follow Bacon’s advice, Turn back from rash theories, and follow observation and experience.

We have hitherto endeavoured to shew that incontrovertible geognostic facts indicate an alternate rising and falling of the water which covered the earth’s surface, but that they were not of a kind to justify the notion of violent revolutions, or of sudden and universal eruptions of the sea; and that, therefore, such deluges as the Mosaic deluge, recorded in the traditions of nations, were not revolutions of this description. If, according to the supposition of Cuvier, the earth’s surface inhabited at the commencement of the latter deluge has become the present bed of the sea, and the former bed of the sea has become the present dry land, then, according to the present state of geography, though only conjectural, we should be able to point out such portions of the earth as were overwhelmed by the catastrophe; and yet we have never heard that any one has hazarded such an experiment. In the constitution of the present habitable globe, we find no proofs remaining of such a revolution.

Among these revolutions of nature, we never reckon common inundations, such as take place at present from water overflowing its boundaries, though these also may produce devastation whose effects remain visible for an hundred years. But, in mountainous districts, another kind of aqueous eruption makes its appearance, and may be classed along with the traditions of a deluge. We very frequently, for instance, observe the valleys of high mountains forming a range of basins separated from one another by shorter or longer defiles, and opening through the last defile into a wider valley, or a marsh. The shape of these basins, or cauldrons, commonly lying above one another like so many stories, and the level surface of their water, leave no doubt of their being once enclosed lakes which were formerly blocked up by the barriers of the defiles, and which flowed towards the level country, as soon as the defiles were broken down by the waters. If no kind of historical monuments in the west of Europe bears evidence of those events, which, at least on a small scale, occur in our own times, this intimates that it was inhabited, not by an original population, but by a foreign or modern race of people; whereas those revolutions extended to remote antiquity. The numerous masses of rock found on both sides of the Alps to the height of 4000 feet, as well as in the plains of the north of Europe, at a great distance from their original position, and concerning whose coming hither so much light has lately been thrown by Messrs Buch and Escher, are a very probable proof of these debacles; while every circumstance renders it evident that these blocks were swept along by the currents thus created, to the place where they are now found. The Greek writers have also preserved accounts of such revolutions, which, although not unquestionably authenticated, are yet stamped with the impress of historical testimony. Herodotus has the following passages directly relative to the country where the Greeks place their second or Deucalionic deluge. “Thessaly must formerly have been an inland sea, surrounded by high mountains. On the east it was bounded by Pelios and Ossa, whose bases were united; on the north by Olympus; on the west by Pindus; and on the south by Othrys. Thessaly lay in the midst of these mountains in the form of a basin, into which, in conjunction with other copious streams, the five well-known rivers, the Peneus, the Apidanus, the Orochomenus, the Enipeus, and the Pamisos, emptied themselves. These rivers, which are collected in their basin from the mountains which encompass Thessaly, after their junction under the name of Peneus, in which they lose their former appellation, open towards the sea through a narrow valley. According to tradition, this valley and opening did not formerly exist; so that the rivers and the Lake Brebeis, which did not formerly bear these names, having their confluence in this place, rendered the whole of Thessaly an inland sea. The Thessalians affirm that Neptune opened the valley for the passage of the river Peneus, and they may perhaps be right. If we consider Neptune the author of earthquakes, and consider the violent concussion of the mountains caused by them as the work of this deity, we must, upon surveying these regions, confess that they owe their present shape to him; for the separation of every mountain appears to me to have been produced by some violent commotion of the earth.” Strabo makes mention of this tradition, which he thought worthy of belief, and accounts for the origin of the Vale of Tempe, which is the bed of the river Peneus, and likewise for the separation of Ossa from Olympus, by means of an earthquake[405]. In making this remark, we perceive that our theories which allow that earthquakes are to operate in forming the surface of the earth, have not even the merit of novelty. According to the last writer, similar eruptions of water must have originated in the lake Copais in Boeotia[406], in the lakes Bistonis and Aphnetis, in Thrace, and have been accompanied with huge devastation[407]. Diodorus Siculus[408] remembered a Samothracian tradition, according to which the Euxine Sea was once shut up on all sides. It afterwards burst through its mighty mound of kyanischen rocks to the Hellespont, and inundated a great part of the coast of Asia, as well as Samothracia itself. An objection started to the possibility of such an event is, that, from the observations of Olivier and General Andreossy, the shores of the Black Sea are, in most places, lower than those of the Bosphorus; and that its waters, therefore, even if they were considerably higher than they are at present, would more readily overflow the former than the latter. But since every rock exposed for such a length of time is daily crumbling down, it is a question, whether the shore of the Black Sea has undergone any alteration since that period; and we know that the eruptions took their direction, not so much from the low situation of the barrier, as from the nature of the rock of which it was constructed, being influenced by the weather, and from the rock itself being rent asunder. Be that as it may, the words with which Diodorus commences his narrative are remarkable, when he says, the Samothracian deluge happened earlier than those of other nations. It at least so far preceded others, that, in the estimation of the Greek historian, independent of the deluges of Ogyges and Deucalion, similar natural occurrences more or less authenticated were received as historical facts.

Finally, the effects produced by the bursting of lakes or debacles do not appear to be out of proportion to the devastation mentioned by the traditions of nations. To abide by our former example, floods which could carry along with them masses of rock of 50,000 cubic feet, were in a situation to bury a whole people; and the few individuals who might be preserved would undoubtedly have handed down the memory of such an event to remote posterity. Other deluges may have arisen from other causes, at a time when, as is shewn by numerous vestiges, lakes and rivers had a much greater elevation than at present; and, therefore, every overflowing of them must have produced greater and more extensive ravages.

From these last local eruptions of water, that is, from single limited districts, arose the mechanical precipitates known under the denomination of Alluvial Soil. Their situation, as the uppermost covering of the earth, as well as their origin, which takes place beneath our own observation, furnishes evidence of their being the most recent mineral formations; and it follows from their nature and connection that they were not produced by chemical means, but removed by the mechanical force of water. Since they, among other things, contain prostrate forests, and abundant remains of land animals, we conclude that they did not originate in the bed of the sea, but were floated and deposited upon the dry land by an overflow of land water. How is it conceivable that these precipitates have been covered by the ocean, since their deposition, and have, by means of an opposite change, become the dry land they are at present; and yet it must have been so, if they are to be considered as intimations of the Mosaic deluge.

The view now given, which is that of Henger in his BeitrÄge, is also advocated by other naturalists, and has lately been brought forward in an interesting manner in the Edinburgh Philosophical Journal[409]. We have been frequently requested to give the two views, in regard to the universal deluge, namely, that which maintains that it is proved by an appeal to the phenomena of the mineral kingdom; the other, which affirms that that great event has left no traces of its existence on the surface or in the interior of the earth. M. Cuvier’s Essay, and Professor Buckland’s ReliquiÆ, are the best authorities for the first opinion; while numerous writers have advocated the second.

Note, p. 244.

ON THE ACTION OF RUNNING WATERS.

A very great degree of power has been attributed to the waters which move at the surface of the earth, or in its interior. Many geologists have advanced the opinion, that they have scooped out the channels and even the valleys in which they flow, and formed the cliffs whose feet they wash; and many philosophers, naturalists and even geologists, still support this opinion, not only in some of its applications, but even in its whole extent.

In order to appreciate it, it is sufficient to observe with care the different modes of action of water set in motion by different causes, and the changes which it has operated upon the rocks and deposits upon which it has acted, from the most remote times to which history may reach.

We must, in the first place, successively examine the different sorts of action of the principal masses of water which are in motion at the surface of the earth, that is to say, the action of torrents, of rivers, of currents of the sea, or of great lakes, and that of waves.

We shall afterwards see what consequences are to be deduced from these observations.

1. Action of Torrents.

Torrents have a true degrading and scooping action upon the earth’s surface, but, by the necessary consequence of the sense which we attach to the word, this action cannot be exercised upon spaces of great extent, for a torrent is a water-course which has a great declivity. Now, on account of the little height which the most elevated summits of the globe have in comparison with the extent of its surface, this action cannot be very extensive; it can only, therefore, produce short and narrow ravines. This action, as all who have visited high mountain chains may have seen, is only often local and instantaneous; it presents no remarkable effect but upon the heaps of debris which cover the declivities of the mountains, and on broken rocks, partially disintegrated by other causes, and lastly on moveable deposits. The results of this action contribute to confine it within narrower limits still, by heaping up at the mouths of torrents in the valleys or plains, the debris carried down by these torrents. The elevation of the soil, which necessarily follows from the accumulation of these debris, diminishes with the declivity, the rapidity, and consequently the power of these water-courses.

Great masses of water moving rapidly, have a marked transporting power. Striking examples of this power have but too often been seen in Holland, by the breaking down of the dikes, and in Alpine mountains, in consequence of extraordinary rains during tempests, or from the rupture of some of the natural barriers of lakes. In these latter times (in 1818), the VallÉe de Bagne experienced the terrible effects of this devastating power. Masses of ice having fallen towards the upper part of this valley, and accumulated there, raised a dike sufficiently compact and strong to block up the course of the Dranse. The waters of this river, rapid and pent up in certain parts of its course, as are all those of the high Alps, accumulated above this barrier of ice, and formed a lake which attained, at its maximum, 130 metres of mean breadth, from 3000 to 4000 metres of length, and 36 of mean depth, and consequently a volume of water estimated at about 29,000,000 cubic metres. Although, by means of operations conducted with equal skill and courage, about the third part of this volume was let off without danger, the remaining part having suddenly broken through the barrier of ice, was precipitated with an almost unexampled impetuosity of 11 metres in the second, into the VallÉe de Bagne. In the first part of its course, and in the space of half an hour which the mass of water took in traversing a league, it carried away trees, dwellings, enormous masses of debris, and rocks already separated from their mass, as M. Escher, expressly says; it covered all the broad parts of the valley with rubbish, pebbles and sand, and carried the remainder of the substances which it had swept away, as well to the extremity of the valley, towards Martigny, as into the bed of the Rhone. The mass of water took an hour and a half in rushing from the glacier to Martigny. The same event took place from the same cause, and with nearly similar results, in 1595.

Torrents may therefore scoop out ravines in certain formations, and produce effects which appear considerable, because we judge of them by comparison with our own feeble means. But how diminutive and circumscribed are these changes produced in the configuration of the globe, compared with the long and broad valleys which furrow in vast numbers the immense surface of the earth, and to the formation of which neither the torrents nor great rivers which exist at the present day have in any way contributed, as we shall presently demonstrate.

2. Action of Rivers.

The action of rivers must be examined under two very different circumstances, or at two different parts of their course.

First, When they are compressed between mountains, whether at no great distance from their source, or even at the middle of their course.

Secondly, When they have reached broad valleys, whose declivity is slight, or plains which commonly surround their mouth.

In the first case, these rivers partake of the impetuosity and power of torrents. They often run with rapidity, and in great quantity, at the bottom of narrow and deep valleys: they are as it were inclosed in channels, whose vertical walls appear as if cut by art. The first idea which presents itself to all who have seen these appearances for the first time, and who are satisfied with first impressions, is, that these streams, which are pretty powerful and always very impetuous, have dug these deep grooves; and if sometimes the hardness of the rocks and the height of the precipices which form their sides, appear too great for those small streams that meander at their feet, what cannot be attributed to their immediate power is attributed to the continued action of time.

Without examining how long a series of ages it would be necessary to admit, before the rivers which we have mentioned above, and the water-courses encased in the deep valleys of the Alps, Pyrenees, Jura, Grampians, &c. could have scooped their valleys, on which their present action is so slow that no one has yet been able to estimate it; without examining if this long series of ages agrees with the phenomena, which preclude our attributing so remote an antiquity to the actual state of the earth’s surface, a question of too much importance to be treated indirectly; it will be sufficient to mention here four sorts of observations, in order to be persuaded, or at least to suspect, that the present rivers, even supposing them ten times the size that they are, could not have scooped out the deep channels at the bottom of which they run.

1. We must recur to the period when the ranges of hills which border the present valleys were not as yet scooped out, but were united in such a manner as not to leave any hollow between them, or merely a slight original depression.

This shallowness of the valley would be accompanied with an inconsiderable slope of its bottom. If, then, we suppose the same mass of water, it must run with less quickness, and consequently with much less power; and yet a very great force must be attributed to it, before it could have had the power of removing a portion of rock nearly represented by a recumbent triangular prism, having often 500 metres of breadth by a sometimes equal and often much greater vertical thickness. If, in order to get rid of this difficulty, we admit a volume of water incomparably larger than the present volume of the rivers to which so great effects are attributed, we must admit much more elevated and more extended mountains, to give rise to so great a volume of water.

Were we only detained by this hypothesis, and did not direct observation oppose itself to the admission of this disaggregating power and its effect, we might pass it over; but two other observations render the hypothesis inadmissible.

2. Historical records equally concur to prove that the rivers possessed of the greatest power which can be attributed to them, have no appreciable corroding action upon the rocks on which they move.

No one has maintained that the greater number of the cascades, cataracts, or rapids, long known and mentioned on account of their celebrity, have disappeared or have even sensibly diminished, nor consequently that the natural dike which the water had encountered in its course, has been worn or even completely disrupted. We do not find that cascades have changed into cataracts, and these again into rapids. The cataracts of the Nile have been spoken of from time immemorial, as always opposing an obstacle to the navigation of that river; the same is the case with those of the Danube, of the fall of the Rhine at Schaffhausen, &c. The famous cascades of the Alps and Pyrenees have been cited ever since writing was in use; and among all these examples we can scarcely find two or three cascades that have been lowered, or cataracts reduced in their level.

The only cascade which we can point out as having really diminished in height, is that of Tungasca in Siberia. We do not, however, assert but that there may be others. So many causes different from those of erosion may concur to lower a cascade, or even make it disappear almost entirely, that we are rather astonished at the small number of examples mentioned, than embarrassed by the objections which these examples might present to the opinion which we are defending: for the fall of a part of the rock which forms the cliff from which the cascade is precipitated; an abundant accumulation of debris at the foot of the cliff; a real destruction of the softer deposits, forming part of the strata of the mountain from which they fall, are sufficient causes for changing the height of waterfalls. These causes must present themselves pretty frequently; but how different is their action from that of erosion? This, if it existed, would extend from the source of the river to its mouth, and would have a considerable influence upon the configuration of the earth’s surface. Those which we have mentioned have, on the contrary, an action so limited and so local, as to be scarcely appreciable.

3. Allowing, for the moment, that a river, possessed of a vast erosive or disaggregating power, may have scooped out the valley in the bottom of which it at present flows, in a state of feebleness very different from its original state, we must account for the disposal of a vast mass of earth and rock, which filled up the valley before the river had removed it. It is not possible to suppose that it has been transported into the sea, which is often more than a hundred leagues from the valley; for we know that when rivers, on reaching the plains, lose their rapidity, they allow the matters to be precipitated which they held in suspension. Besides, we have shown that many rivers, on leaving the mountains, traverse lakes, in which they deposit all the earthy matters suspended in their waters. This deposition is particularly striking in all the considerable rivers, which descend from the ridge of the Alps toward the north-west and south-east of that chain of mountains. These rivers meet, at the opening of the valleys they flow through, lakes, which they traverse, and which seem intended for their purification. Thus, on the northern side, we see the Rhone traversing the lake of Geneva; the Aar, the Lakes of Brientz and Thun; the Reuss, the Lake of the Four Cantons; the Linth, the Lake of Zurich; the Rhine, the Lake of Constance. On the south side, the Lac Majeur is traversed by the Tessin, the Lake of Como by the Adda, the Lake Disco by the Oglio; the Lake of Guarda by the Mincio, &c. Now, these lakes, which are only themselves deeper parts of the valley, would have been filled up by the debris conveyed to the valley, if this valley had the origin attributed to it. Proceeding from one hypothesis to another, it might perhaps be supposed that these lakes may have been sufficiently deep to swallow up all the debris of the valley, without being chocked up. But, rather than admit such suppositions, why not grant that the same unknown cause which has scooped out the lake, has also scooped out the valley which is only a continuation of it?

4. But if facts had proved that the waters degrade the rocks, scoop them out, and perpetually remove their debris, we might perhaps be induced to admit that unknown causes, of which we are absolutely ignorant, and of which we can form no idea, have given to the original rivers the means of surmounting all these obstacles. Now, observation would seem absolutely to prove the contrary.

We have remarked, that rapid rivers which, in the bottom of valleys, fall in cascades, from rock to rock, which beat with violence against the walls which contain them, do not in any degree alter these rocks, and that, far from corroding their surface, they allow it to be covered with a rich coating of mosses, confervÆ, &c. which could neither maintain itself, nor be formed at all, were the least portion of the surface of these rocks continually or even only frequently removed.

A much more striking fact is that which some of the great rivers present, such as the Nile, the Orinoco, &c. which flow in the equatorial regions.

These powerful rivers, when they have arrived at places where they are contracted, and, as it were, jammed in between two rocky walls, form impetuous cataracts. Their waters, endowed by the celerity of this fall with the greatest erosive power that can be attributed to this fluid, must necessarily have corroded, or at least worn, the rocks which they have thus beat against since the creation of our present Continent. Now, so far from removing the surface, they cover it with a brownish varnish of a peculiar nature.

It appears, therefore, well established, that water alone does not scoop those rocks, whose aggregation is complete, or which are solid; and that it does not wear them in any way, whatever be its quantity of motion.

We say water alone; and we must insist on this distinction, in order to make the preceding facts agree with other facts, which might seem contradictory.

We often see furrows scooped out on the walls that bound the narrows of rivers; we also see rocks rounded, and entirely destitute of moss. But let the facts be examined with attention, and we shall find that this erosion always takes place in the parts of their course, where, on account of the nature of the neighbouring soil, the torrents carry with them, in their risings (or floods), debris and detached stones from their banks; and it is by means of these stones that they wear the rocks which are in their bed.

It is very easy to appreciate these circumstances. It is remarked, that this erosion has never taken place at the sources of powerful springs. All the pebbles which had to be carried off have been so long ago, and the mosses which grow abundantly on the rocks at the level of the water, and in the bed of these torrents, have nothing more to fear from the destructive action of these solid bodies. The case is the same with the parts which immediately succeed a lake, or a great excavation, capable of arresting all the hard bodies carried off by the river. There the mosses appear in abundance; because they are not subjected to the action of any other substance than of the water alone.

The present rivers do not therefore appear to have any erosive power upon the rocks which are completely aggregated, when they act by themselves, and when no other cause, such as frost, decomposition, &c. has disintegrated the rock. The absence of these foreign circumstances is proved by the vegetation or the enamel which then cover the rocks exposed to the action of the water.

These rivers, in proportion as they remove from the rocks in the neighbourhood of the lofty mountains in which they took their rise, often gain in volume what they have lost in velocity; but the power dependent upon size rarely compensates that which they owed to rapidity; and although these large rivers still retain a transporting power, sufficient to carry along with them the obstacles which oppose themselves to their progress, they are far from presenting results of action so striking as those of torrents. They stir up, when flooded, or when they change place, the earth and mobile sand which cover their bottom, especially towards their edges, and transport them to some distance; but they scarcely move pebbles larger than an egg, which occur in their bed, and which have been brought there in other times, and under other circumstances. On thus transporting the comminuted and mobile mineral matters, they deposite them again in places where their current is relaxed by some cause, and thus raise the bottom of their bed in these places; they seek a new passage in the midst of the barriers which they have themselves constructed. The principal current is then borne, sometimes against one bank, and sometimes against the other; and when it comes to beat upon the foot of a steep part, composed of moveable soil, as the banks commonly are, in such cases, they really erode it, and make it fall into the river; and transport to another part of its course, the earth resulting from the destruction of the bank, and give rise to new obstacles. Hence the new deposites, which border rivers in all points where their current is slackened, and principally toward their mouth. It is sufficient for our present purpose to have referred to facts remarkable for their number, for the importance which they have had in regard to the modern changes of the configuration of the globe; and, lastly, in regard to agriculture and civilisation;—facts of easy observation, and which tend to prove, that the action of rivers, whose fall is not sufficiently rapid to entitle them to be considered as torrents, is not to scoop out their bed, either in the valleys or in the plains through which they flow, but rather to raise them, and to tend, consequently, rather to level and flatten the earth than to furrow it, more than it has been since the Continents have assumed the configuration which they now possess.

But if we have not been able to recognise a real corroding power in the great rivers falling in the form of cascades or cataracts, let us inquire elsewhere, in circumstances where the water seems endowed with a still superior power, what are the effects of this agent?

3. Action of Waves.

It is in the sea, an enormous mass, sometimes acquiring, from the action of the winds, an incalculable power, that we must find the maximum of force of the water of the present times. In fact, in this case, the power of transportation is so prodigious, that the strongest barriers, both natural and artificial, are overturned, and the largest stones, together with enormous fragments of rocks torn from their place, transported, and even projected to a distance. But it is to these effects that this immeasurable power is limited. The water, which displaces and transports to a distance these heavy masses, does not abrade the surface when it acts by itself. We see this surface, on rocks and the sides of piers and dikes, perpetually beaten by the waves, covered with fuci, confervÆ, byssi, and other delicate vegetables, without roots, which the waves have not prevented from contracting a first and feeble adherence, and which they do not hinder from growing. But, if the waves carry with them pebbles, or even sand, it is those hard bodies which act; the surface of the rocks is abraded, and all vegetation ceases.

The same effect takes place, and is even augmented by the real degradation of the coasts, if the sea acts upon friable rocks, capable of mixing with water, such as argillaceous or calcareous marl, or chalk, or upon rocks which are hard, but naturally fissured, or partly disaggregated, such as certain granites; it then easily removes the crumbled or previously detached parts, scoops out the foot of the rock or steep coast, and causes the upper part, which is deprived of support, to fall. But, in consequence of this fall, it forms a slope, which, by its inclination, deadens the violence of the shock, and even protects the foot of the cliff, for some time only, if it be friable, or capable of disintegration; and for ever, if, being compact, it does not carry in it the causes of destruction. The action of the waves ceasing, the slope is covered with vegetation; and if the coast continues, nevertheless, to be worn, the changes are then owing to causes unconnected with the action of water.

Such is, in few words, the ordinary action of the water of the sea upon steep coasts, and even that of great masses of water in a state of agitation. M. De Luc, in his various works, has estimated this action with a correctness of observation and of reasoning, which is remarkable only, because it has not been adopted by all naturalists; and few have bestowed the unremitting attention upon the subject which this respectable geologist has done. He has shewn, that the destructive action of the waters upon steep shores, and other coasts or abrupt cliffs, was considerably restrained by the very consequences of this action; that the debris which accumulated protected the lower parts of these coasts from the action of the water, or gradually reduced an abrupt coast to a very inclined and permanent slope.

Next, to torrents, to rapid and large rivers, and to waves, it is to currents that a great influence on the earth’s surface has been attributed,—an influence which a highly gifted naturalist, Buffon, has employed to explain all the inequalities of the earth’s surface.

Our knowledge of the action of currents is less precise than that which we possess of rivers. But if we cannot so visibly demonstrate that, in no circumstance similar to those which we have specified, do they scoop out the bottom of the sea into valleys, nor form any mountains, we can, at least, conjecture with much probability, and maintain, that we have no direct and constant proof of that action.

4. Action of Currents.

No one doubts that currents, near coasts, heap up upon the beach, at the mouth of rivers and harbours, pebbles, sand, gravel, mud, or other transportable matters, whether these currents constantly exist, or simply result from the momentary action of a predominating wind; but this action, although already limited to the mobile matters which form the bottom of the sea only in some parts, whether this action, I say, extends to a great depth, that is to several hundred yards, is a question not yet resolved. In the first place, the observation made by mariners, that, in the most violent tempests, the sea is only agitated towards the coasts, or on shallows, and that bodies, sunk to a great depth, (and still what is this depth in comparison with that of the sea,) do not feel the motions of its surface, nor that of currents; and, secondly, reasoning, and even calculation, according to Messieurs La Place and Poisson, concur to shew, that the violent motions of the waters of the sea are not propagated to a great depth. It is therefore probable, that all the transportable matters, which are at this depth, must remain nearly in the position in which they are, since our Continents have assumed their present configuration, unless phenomena and motions of the sea take place at the bottom, of which we are ignorant, and which are foreign to the subject which at present occupies our attention.

But if we have no perfectly certain ideas regarding the propagation of the motions of the sea in depth, we can assert, that, whatever that extent and that power may be, the submarine currents no more abrade the rocks than rivers do the surface of the land. This proof is always derived from the same kind of fact, namely, from the vegetable and animal bodies which constantly cover the rocks, and which are found, at all times, by means of various sorts of dredge-fishing. In fact, no one has remarked, that the places in which oysters, mussels, corals and sponges are fished, are more sheltered from currents than others; nor that these places, after violent tempests, have been deprived, and consequently, as it were, despoiled of those productions, which, by covering the rocks, demonstrate that they preserve the integrity of their surface. Many of these bodies, however, as sponges, fuci and confervÆ, contract but a feeble adherence to the bodies upon which they are placed.


It therefore appears, if not completely proved, at least extremely probable, from the facts and reasonings which we have related,

1. That the presently existing waters, that is to say, in the state of purity in which we are acquainted with them, have no erosive action upon rocks, whatever be the nature of these rocks, when, 1st, The rocks are completely solid, and when they are neither friable nor disintegrated; 2d, When these waters act by themselves, that is to say, when their action is not complicated with the really erosive action of solid bodies, such as pebbles, sand, and perhaps even pieces of ice.

2. That water, sometimes acquiring, on account of its quality and velocity, a great transporting power, may remove masses, already detached, and of great size, according to its degree of velocity, and the bulk of its mass, and so far as it preserves this same power.

3. That the presently existing waters may have attacked, undermined, and caused to fall down, portions of solid and steep rocks, by mixing with beds of clay, marl, and sand, interposed between their solid strata; that they may also, in their rapid falls, have scooped pretty deep ravines in very inclined deposites, consisting of disintegrated rocks; but that these waters could not have scooped out, either by a violent action, or by a slow one, however long continued, any of those long and broad longitudinal depressions, which are named valleys, or of those narrow openings, with almost vertical walls, which are named gorges or ravines.

4. That, even when the deposites, which border these valleys or these ravines, are composed of transportable matter, the waters which at present flow in them could not have scooped them out, even supposing them to have been much larger in some than they now are; the declivity of the present deposite not being sufficiently great to give to these masses of water the rapidity necessary for producing this effect, and a power sufficient for carrying off the moveable matters which filled the valley or gorge.

5. Lastly, that the present running waters, so far from having contributed to form the numerous valleys, glens, gorges and ravines, continually tend to fill them up, and rather to level the surface of the globe than to furrow it, more deeply than it is.

Vid. Brongniart sur l’Eau.

Note

On the Connection of Geology with Agriculture and Planting[410].

That all sorts of soils are not equally adapted to all productions, is a remark of Virgil’s, the truth of which becomes obvious, when we consider many facts ascertained in Agriculture and Forestry. If, therefore, as the poet advises, our object be to determine what each particular region can produce, and what it cannot, our attention ought in the first place to be directed to the physical circumstances which exert their influence over vegetation.

All plants that are the subject of cultivation are fixed in the ground. By one of their parts, through which they derive their principal nourishment, they penetrate into the soil, which serves them as a basis, and affords them the means of procuring subsistence; by the other part they raise themselves into the atmosphere, which is not only necessary in itself for their existence, but is also the medium through which they derive the warming and vivifying influence of the solar rays. Hence we can understand how much the existence of plants must be influenced by differences in the condition of the soil and air.

The superficial crust of the globe is formed of soil capable of producing vegetables. This productive soil, however, is not everywhere continuous, being interrupted on the one hand by the watery covering of the earth, and on the other by perennial snow and bare rock. Where soil does occur, it separates the solid mass of the earth from the atmosphere, and is the porous medium through which the gaseous and watery parts of the latter may act in a greater or less degree upon the former. It is very seldom that strata of vegetable soil lie beneath strata of other matters; and where they occur in this position, the overlying strata are either of volcanic or of alluvial origin. Of the former case, a very remarkable example occurs in the Isle of Bourbon, in which large tracts covered with vegetables and even trees, have been laid waste and overwhelmed by streams of lava; and large rivers in their overflowings occasionally leave deposits of various characters, over the productive soil containing remains of formerly existing plants.

Productive soil, as well in regard to its situation as to its constitution, depends upon the nature and condition of the rocks which form the solid mass of the earth. It is always of secondary formation, compared with the rock on which it rests, its principal parts usually originating from the decomposition of this rock. While the forms of the surface of the solid mass of the earth, have much influence upon the action of the atmosphere, they also in some degree modify that of climate. From these circumstances it would appear that the solid substrata of productive soil exert an influence in various ways upon vegetables; whence it follows that, in order to obtain a more intimate knowledge of the conditions which operate upon their existence, it is necessary to call in geology to our assistance.

Although the scientific study of agriculture has made great progress in our times, the relations which exist between the constitution of the solid crust of the earth, and the formation and nature of vegetable soil, present a wide field for investigation. Geologists have hitherto too much neglected the examination of the productive covering of the earth, and those who have treated scientifically of agriculture and forestry have usually looked upon the vegetable soil in its own simple capacity, without regard to its foundation and origin. To point out the way by which we are to proceed in our investigation of the relations which exist between the solid crust of the earth and the productive soil which covers it, is the principal object of the following observations.

Bare rocks cannot be made subservient to the purposes of agriculture. Lichens indeed, cover the surface of rocks, deriving their chief nutriment from the atmosphere; mosses draw the water necessary for their subsistence from the fissures of stones; the roots of grasses seek in the chinks of rocks for particles of earth sufficient for their sustenance; various shrubs and trees penetrate here and there into rocky masses by their roots (having the powerful and continued action of living wedges), where the cohesion of the parts is smallest, in order to prepare a fixed seat for themselves, and be secure from the pernicious effects of the atmosphere. The surface of the earth is always sterile, however, when it shows a continuity of naked rock, uncovered by vegetable mould. The cultivation of fields and woods, and even the rearing of cattle, cannot therefore find scope in regions which are entirely rocky. Abrupt and precipitous mountains being generally in this condition are usually barren; but in plains and on declivities, a bare rocky surface is much less frequently the cause of sterility than an unfavourable proportion of mould. Some rocky and moderately elevated regions also occur, more or less destitute of vegetable mould, whose sterility depends upon volcanic causes. Iceland, for example, affords cases of this description. In many parts of Sweden, as in Westrogothia, in Scotland, &c., there occur many elevated regions, in which gneiss and granite predominating, exclude to a great extent all kinds of vegetation excepting lichens. In the same districts we sometimes meet with pastures and corn-fields interrupted here and there by bare rocks rising but little above the surface, by which the value of the ground is much diminished, and great impediments opposed to its cultivation.

As bare rocks are incapable of all cultivation, their distance from the under surface of vegetable mould must also be of great importance. In the plains of the north of Germany, for example, this distance is often so great that a rocky surface is never found, while, on the contrary, in other countries, especially such as are mountainous, the roots of plants not unfrequently touch the subjacent rock; the variation between these extremes being of all degrees. The effect of the distance of the surface of the solid rock from the under surface of productive soil may be both direct and indirect, and may vary much, not only with reference to the species of rock, but also to the vegetables.

The surface of the solid strata of the earth has a direct influence upon the cultivation of plants, because it terminates the extension of their roots, and limits the volume of the soil necessary for their sustenance. As the length and direction of the roots vary exceedingly in different species, the difference of effect with regard to their growth, and the approximation of the rock to the under surface of the soil, must in general be so much the less prejudicial in proportion as the roots decline from the perpendicular; whence it follows, that certain grasses, and some small pasture plants, may grow in very thin layers of soil, where the larger grasses and pasture plants with longer roots, could not find subsistence; and that shrubs and trees, with long perpendicular roots, cannot survive in many places, where others with more horizontal roots may thrive. These inferences are proved to be correct by observations in agriculture and forestry generally known.

Mountainous regions, which are not so elevated but that corn might grow sufficiently well in them, in so far as depends upon the conditions of the air or climate, are yet frequently not adapted for its cultivation, on account of the too near approach of the rock to the surface, or shallowness of the soil, and produce nothing but grasses, and some other pasture plants, among which, however, there is the greatest difference in this respect. Trifolium montanum, for example, can support itself on rocky mountains, where T. pratense could not grow. Hedysarum onobrychis grows luxuriantly on the sunny declivities of calcareous mountains, where Medicago sativa (Lucern) does not find a suitable station. The cultivation of this excellent pasture plant in some mountainous regions, especially where the rocks are calcareous, has not proved so advantageous as might have been expected, because the plants have died out in the course of a few years; whereas, in proper places, where its very long roots find a sufficient depth of soil, they usually last for a great length of time.

The vicinity of the rock to the under surface of the vegetable mould, or the shallowness of the soil, seems to be the principal cause why the Beech grows better on many calcareous mountains than the Oak, which, on the other hand, finds a fitter station on mountains in which sandstone predominates, where the soil is usually deeper. It would seem to be for a similar reason that the Beech grows in many rocky districts, for example, on the Hartz Mountains, at pretty considerable heights, especially on the sides of valleys which run to the south, while these places do not admit the Oak, which is found in the middle provinces of Sweden and Norway; while the Beech, on the other hand, grows only in the southern parts. From the deficiency of soil, the Upper Hartz can produce neither the Pinus pinea, nor P. sylvestris; the horizontal roots, however, of the Abies, or Norway Spruce, are content with the small portion of earth which covers the greywacke and slate, although they cannot find sufficient hold to protect its lofty trunks from being thrown down by the tempest. In some parts of the Forest of Thuringia, where the covering of loose earth is deeper than in the Hartz, the Pinus picea, or pitch pine, grows luxuriantly. The common fir, Pinus sylvestris, which attains a great height in proper soil, on the contrary, is stunted and distorted on rocky mountains, where the roots soon come in contact with the rock. It there loses the character of a tree, and assumes that of a shrub, as in place of a single upright stem, several branches shoot out, and these, not unfrequently, are creeping or bent.

The different conditions of rocks, especially their structure and their state of cohesion, are of some importance in producing these effects; for the surface of rocks must be detrimental or impervious to the roots of plants, in proportion to the compactness of their structure, and the cohesion of their parts. Schistose rocks, for example, afford a more easy passage to roots, than granular crystalline ones; pure quartz resists the roots of plants in the highest degree; sandstone much less; and pure limestone, on account of its comparatively small number of fissures, is much less favourable to vegetation than marl, chalk, or slightly cohering calcareous rocks, the masses of which are usually split in all directions.

The direction and inclination of the strata have also some influence in this matter; for, in proportion as the principal fissures of the strata are, from their direction or inclination, more readily presented to the roots of vegetables, the less prejudicial will their surface be to vegetation. Horizontal strata, therefore, are the least favourable to vegetation, perpendicular ones the most. In the inclination of strata intermediate in some degree between these positions, the roots of vegetables will find a greater obstacle on the side of a hill in which the surface of a stratum is opposed to them, than on the other, in which the principal fissures of the strata are open. The effects of this circumstance may frequently be observed in mountainous tracts having two principal inclinations, the state of vegetation, and especially the growth of wood, being more prosperous on the one of these declivities than on the other.

The surface of the solid strata of the earth may also have an indirect influence upon the cultivation of vegetables. The various inclinations of this surface deserve first to be considered, being of the greatest effect with regard to fixing the fertile soil. The horizontal position of a rocky surface is in the highest degree favourable to the stability of vegetable earth; and the greater its angle of inclination, the greater is the danger of its losing the soil upon it. In a highly inclined plane, the imperfect support of the centre of gravity is the sole cause of the loss of earth; in a less inclined plane the diminution of soil is usually caused by water, which produces this effect in a greater or less degree, according to the difference of inclination. In both these modes, by which a removal of soil is produced, the effect may be modified by a difference in the condition of the loose earth, as not only its stability as to situation, but also its resistance to the power of water, vary according to the size, figure, and cohesion of the parts, as well as their adhesion to the surface of the rock. Sandy loose soils, for example, are more liable to transposition than marly or loamy ones; and these, again, are more easily moved than such as are clayey and adhesive.

Whatever be the nature of the soil, a small degree of inclination in the solid rock is sufficient to favour its denudation by the removal of the former; and the inclinations of the surfaces of rocks having a covering of earth and vegetation, are in reality much less considerable than we usually suppose them to be, judging merely by the eye. The celebrated Humboldt has published observations on this subject. According to his measurements, a slope of even fifteen degrees appears steep, and a declivity of thirty-seven degrees is so abrupt, that if it be covered with a dense sward, it can scarcely be climbed. The inclination of the pastures of the Alps seldom exceeds an angle of ten or fifteen degrees, and a slope of twenty degrees is pretty steep. At an inclination of forty degrees, the surface of the rock is sometimes covered with earth bearing a sward, but at a greater inclination the rocks are usually destitute of soil and vegetation. In the Upper Hartz, the most common inclination of the declivities of the mountains is twenty-five degrees; nor does it usually exceed thirty-three, at which inclination the beech and spruce grow. The greatest declivities at which ground can be advantageously cultivated have an inclination of thirty degrees.

The roots of vegetables, especially of grasses, shrubs, and trees, are of much importance in supporting the earth upon the declivities of rocks. Care must therefore be taken that the declivities of mountains which are covered with turf or wood, be not altogether deprived of these coverings, as sometimes happens in consequence of loosening the turf for agricultural purposes, or of incautiously extirpating the wood. In Norway, near Roraas, there occur mountains, destitute of all vegetation, that had formerly been covered with woods, but where now, from the deficiency of soil, no seeds could take root. The same is the case in many parts of the Alps, where, from the irregular long-continued removal of the timber, the sides of mountains which were formerly covered with thick woods, now show nothing but naked rocks. For this reason, in mountainous countries with very steep declivities, the breeding of cattle and planting of woods are often more advantageous than agriculture. In France the greatest inclination of the public roads is limited by law to an angle of four degrees and forty-six minutes: a similar restriction with regard to agriculture might not be without benefit in certain mountainous countries.

The inclinations of the surface of the solid crust of the earth vary much, according to the different qualities of the rocks; some having a tendency to form abrupt precipices, others, again, to produce gentle declivities. For this reason, mountains consisting of quartz or porphyry, for example, very frequently present surfaces destitute of vegetation; while, on the other hand, those of granite, slate or sandstone, are more frequently adapted for agriculture and planting. In the northern parts of Scotland, quartz rocks, destitute of all vegetation, rise in the midst of mountains covered with gramineous plants, and sometimes wood. In the most fertile part of the south of Norway porphyritic mountains rise from a calcareous and schistose base, with lofty, rugged, and bare cliffs. In the southern parts of the Tyrol the rocky sterility of the abrupt and lofty porphyritic mountains presents a striking contrast to the fertility of the neighbouring limestone mountains, which are covered with vines, walnuts and chesnuts.

The surface of the solid strata of the earth has also an indirect influence upon the cultivation of plants, in so far as the water which the vegetable mould acquires from the atmosphere, is retained in the soil, or is drawn off by the subjacent rock. Different rocks produce very different effects in this respect, depending as well upon their constitution as their structure. The component parts of rocks imbibe water in different modes and degrees; and different sorts of rocks not only attract water with different celerity, but also imbibe different quantities of it. The latter difference depends chiefly upon the various substances of which rocks are composed, partly, also, upon their porosity. Siliceous rocks attract water in the lowest degree, argillaceous ones in the highest, and calcareous rocks appear to have an intermediate action in this respect. Compact and granular crystalline rocks attract water in a smaller degree, and more slowly; friable or crumbled rocks imbibe it in greater quantity, and with more celerity than those which are not disintegrated. The condition of rocks with regard to the attraction of water, affects, in a different manner, the humidity of soil; for, by this attraction, moisture may as well be abstracted from, as imparted to, the loose earth or soil by which rocks are covered. Part of the moisture which vegetable earth or soil derives from the atmosphere passes into the subjacent mass of rock, but this may again be compensated by evaporation; on which account the soil of such rocks as have but a small attraction for water usually dries up more readily than soils whose solid substratum attracts and retains the moisture in a greater degree.

It is probable that the structure of rocks has also a greater, and not less, diversified influence upon the humidity of productive soil. Solid rocks, which are not traversed by numerous perpendicular fissures penetrating to a considerable depth, allow the water to remain in the soil; but columnar and schistose rocks, with perpendicular fissures, and strata declined from the horizontal position, draw off the water from the soil covering their surface, into lower places, where it often re-appears under the form of springs. In these circumstances, we find a partial explanation of the great difference between the humidity of soil covering a surface of solid granite, and that lying upon limestone, which is intersected by numerous fissures. Granitic mountains are often furnished with marshes, whereas, on the other hand, the dryness of the soil upon calcareous mountains is generally excessive[411], the cause of which phenomenon is, in a great measure, to be attributed to the circumstances above mentioned. Columella observes, that silex having a moderate covering of earth, preserves to the latter its humidity; and Palladius repeats the remark. In districts which consist of quartzose rocks, not less than of granitic ones, the surface is often covered with marshes. Porphyritic rocks, on the contrary, which have a remarkable segregation of parts, as well as columnar basalt, let off the water to lower places. Springs are very frequently found at the bottom of basaltic mountains; for the atmospheric waters penetrate by the perpendicular fissures to the strata on which the basalt rests, and appear at the place where the two rocks meet.

The effect of different rocks upon the preservation and diminution of the moisture of fertile soil, influences vegetation in various degrees. The retentive power of the surface of rocks is of the greatest importance, where the soil consists chiefly of sand, through which the water percolates, and passes off entirely, unless it meets with a stratum of such a nature, as to obstruct its passage, or comes upon a surface of solid rock. The cause of the sterility of sandy plains is not merely their sandy nature, but also the great depth of the mass or rock capable of retaining the water. The same sand, when covering mountains consisting of sandstone, has a much less degree of sterility than in those plains, because the surface of the subjacent rock impedes the progress of the water, and consequently retains it in the soil[412]. It has been sufficiently proved by experiments, that plants can grow in pure sand, when furnished with the necessary quantity of water. A subjacent rocky surface has an entirely different effect upon soil which is very retentive of moisture, upon a clay soil for example, as, in that case, the humidity is increased to a prejudicial degree. In land of this nature, a substratum of rock having the property of drawing off the water would be useful.

The different conditions of rocks with regard to caloric, may have some indirect influence upon the vigour of plants. Heat, whether imparted to the vegetable soil by the sun’s rays, or generated by various chemical processes in the earth itself, penetrates to the surface of the subjacent rocks, and is more or less drawn from it in a longer or shorter time. Columella observes, that rocks in the upper part of the soil are prejudicial to vines and trees, but in the lower part cool them. The heat of soil will be more or less drawn from it, according to the greater or less conducting power of the subjacent rock. Compact crystalline rocks are probably better conductors of caloric than those which are of looser texture; siliceous rocks than argillaceous and calcareous ones. The influence of the subjacent rock must be greater in this respect, in proportion to the thinness of the superincumbent soil. The effect of the abduction of caloric is more particularly sensible, where the roots of cultivated plants touch the rock, a circumstance which we often see in vineyards. The vine frequently thrives remarkably on the declivities of mountains, in which it sends its roots among fragments of stones. Experience shows, that the quality of wine is influenced by the different conditions of the stones, among which vines are planted. Albertus Magnus has observed, that the vine thrives well in earth which is mixed with fragments of black roofing slate; and Humboldt remarks, that the vines which grow upon the mountains of the valley of the Rhine, consisting of black clay-slate, afford an excellent wine. At the Cape of Good Hope, also, the vine thrives well in a soil produced by the decomposition of clay-slate, and mixed with fragments of it[413]. It is probable, that the adaptation of this sort of soil to the cultivation of the vine, depends upon its slow conducting power, and upon its rapidly imbibing the rays of the sun, on account of its dark colour, and thus increasing the heat of the ground.

Hitherto we have only spoken of the proximate influence of rocks upon plants; but it cannot be denied, that the remote effects which they produce, (inasmuch as vegetable soil is derived from them, and, therefore, the qualities of this soil depend in a great measure upon their nature,) are of greater importance.

It is from the rocks which constitute the crust of the earth, that the principal portion of productive soil is derived. Although other substances belonging to the animal and vegetable kingdoms, are necessary for the nourishment of plants, a soil consisting chiefly of inorganic particles is still more necessary, both for sustaining their roots, and for receiving, retaining, and partly also preparing nutrition for them; for, according to accurate observations, some inorganic substances exert an influence upon the decomposition of animal and vegetable remains. These effects vary much according to differences in the aggregation and chemical nature of the inorganic parts; of which circumstances, however, the different qualities of rocks are the ultimate cause.

Two kinds of productive soil may be distinguished with regard to their origin. The soil has either originated in the place in which it now is from the subjacent rock, or it has been transported to the places in which it is now found by some power, especially by that of water. The first kind may be named untransported, the second transported soil. To the first kind of soil is to be referred a great part of the soil which covers the summits and declivities of mountains, and to the other, the soil which fills the bottoms of valleys, as well as a great part of the loose soil of extensive strata in hilly countries and plains. Untransported soil is generally thinner than the transported; and of the two the latter is that which most frequently occurs in low land. The first kind of soil, the untransported, is found to be more or less similar, in its principal constituent parts, to the rocks from which it has originated; in the other kind, the transported soil, on the contrary, the parts which were originally in connection, have been variously separated and mixed, by the agency of the powers by which its transportation was effected.

The quantity and quality of the soil derived from the disintegration of rocks, must depend upon the nature of these rocks; its quality being determined by the constituent parts of the rock from which it originated, and its quantity being proportioned to the greater or less degree in which the rock may resist decomposition.

The disintegration of rocks, and their conversion into loose earth, are partly mechanical, and partly chemical. The principal mechanical powers, by which disintegration is effected, are, 1st, The weight of the loosened parts; 2d, Water, not merely in its liquid and mobile state, but also, and that chiefly, in the state of ice; 3d, The roots of vegetables in general, and especially of trees. These powers usually act more or less in conjunction, and the effects produced by this union are in many cases almost incredible.

The disintegration of rocks commences in those parts where the power of cohesion is least energetic. Rents take place owing to the unequal attraction of parts, and also in the direction of planes, in which heterogeneous parts are in contact; and in this manner the original structure of rocks determines the first steps of their disintegration. Water, which enters into the minute fissures of rocks, by the power of capillary attraction, is expanded by congelation, and thus overcomes the cohesion of parts, and produces rents. The roots of trees acting as wedges, produce the same effect in a wonderful degree, a phenomenon which has been so well illustrated by AnnÆus Seneca, in his Natural Questions. “Let us consider,” says he, “how great a power is exerted by the most minute seeds, which, although at first small as they are, can scarcely find a place in the crevices of rocks, yet at length grow to such a size as to rend asunder vast rocks, overturning crags and cliffs, by the power of their very minute and delicate roots.” The parts of rocks loosened by these powers, are entirely separated, and are carried to a great or less distance, by streams of water, and in the higher regions, by the power of winds. In cliffs and precipices which have been formed by the splitting of masses of rock, effected in the manner above described, the loosened parts often lose their stability; and, following the direction of gravity, fall to the ground, an effect which has also been described by Seneca in another place. “Nor is it alone probable,” says he, “that rocks are split asunder by their mere weight, but also when streams of water are carried over them, the continual moisture works into the joinings of the rock, and daily takes away a portion of the connecting matter, and, if I may so speak, abrades the skin by which it is contained. At length, in the course of ages, this gradual detrition so much diminishes the supporting parts, that they can no longer sustain the weight. Then masses of vast size fall down, and the rock tumbling from its ancient seat, overwhelms whatever lies below.” The cohesion of some rocks, especially argillaceous ones, is so slight, and their porosity so great, that their smallest parts imbibe water, and are sensibly softened by it, an effect which is much assisted by the freezing of the water. This mechanical change is experienced by the different varieties of common clay, slate-clay, and some other rocks.

Chemical powers often act in conjunction with mechanical ones, in breaking down rocks, the former, the chemical, frequently finishing what had been begun by the latter. Mechanical powers only changing the aggregation of rocks, may break down their parts to a certain size, according to their different nature; chemical powers, again, which change the nature of substances, destroy the connection of the minute parts of rocks. When chemical is preceded by mechanical action, it is much assisted by it. The latter has a much more general effect, as all rocks are subjected to its influence; chemical decomposition, on the other hand, acts only upon some rocks, and in these only upon certain parts. The chemical decomposition of rocks is chiefly effected by the oxygen of atmospheric air and of water; but we are also persuaded, that certain cryptogamic plants, intimately attached to the surface of stones, Lichens namely, assist in their destruction.

The oxygen of air and water can only affect the constituent parts of rocks, which have a great affinity to it, such as the iron and sulphur forming pyrites, oxydulous iron, oxydulous manganese, or the same substances mixed with earth or carbonic acid, charcoal and bitumen. Very solid and compact masses of rock, such as greenstone, which are not easily affected by other means, are sometimes corroded by the chemical change of the pyrites contained in them, by which it is converted into a hydrate of iron[414]. In certain other rocks, which are also readily broken down by mechanical agents, clay-slate for instance, the disintegration is much accelerated by the decomposition of the pyrites. The oxydulous iron of felspar is commonly converted by decomposition into a hydrate or ochre. The carbonate of iron, as well as of manganese, which sometimes occur in rocks, in limestone rock for example, are deprived of carbonic acid by the oxidation of their bases. Charcoal and bitumen, which are sometimes contained in rocks, limestone and argillaceous ones for example, are dissipated by the contact of air, so that rocks which were originally of a dark colour, lose it, and become whitish. Water, as a chemical agent, contributes so much to the decomposition of certain rocks, that, either in a pure state, or in combination with carbonic acid, it dissolves their parts, of which gypsum and limestone afford examples. In certain other minerals, in felspar for instance, a separation of the constituent parts, produced by the contact of air and water, is observed, the proximate cause of which has not hitherto been discovered. The mass is decomposed, its lamellar structure is converted into an earthy nature, the alkali contained in the felspar is extracted by the water, a mineral is produced, to which the Chinese have given the name of Kaolin, and which is adapted for the manufacture of porcelain. Granite and gneiss occur in some districts, the felspar of which is decomposed in this manner through the whole mass,—a circumstance which must be of great importance in regard to the formation of productive soil.

Cryptogamic plants covering the surface of rocks, and thriving well in this situation, where more perfect vegetables could not grow, seem also destined to promote the chemical decomposition of rocks, an effect which they produce both directly and indirectly. As they imbibe the water of the atmosphere, and retain it like a sponge, they keep up a constant application of this substance to the rock, and in this manner contribute indirectly to its decomposition. There are some cryptogamic plants also, which consume certain portions of the rocks with which they are in contact, corrode their surface, and destroy the cohesion of its parts, effects which may chiefly be seen in certain cryptogamic plants attached to calcareous rocks. In this manner one sort of vegetation prepares a place for another, and the most imperfect vegetables are subservient to the growth of the more perfect.

After premising thus much, we shall now proceed to the examination of the principal rocks, in so far as regards their connection with the formation of productive soil, beginning with those which resist decomposition in the highest degree, and ending with those which are the most conducive to the formation of loose earth and soil.

In the first class, we place those rocks which experience no chemical decomposition, in so far as regards their principal mass, and whose cohesion of parts is so great that mechanical powers can only open their natural fissures to a greater extent, and thus break them down into fragments. Of this kind are vitreous lava, pure quartz, compact quartz, flinty slate, and porphyry with a siliceous basis. On mountains consisting of these rocks, scarcely any productive soil is found, and frequently none at all. They are usually characterized by sterile rocks and cliffs, the bases of which are covered with innumerable rough fragments of stones, retaining their sharp edges for a great length of time, the heaps of which seldom produce any thing else than mosses, which frequently cover the interstices of fragments, occasionally a few grasses, and sometimes a solitary shrub or tree. Examples, Bennevis, Paps of Jura, and Morven Hills. Of all rocks, vitreous volcanic productions are the least capable of contributing to the formation of productive soil. Their dark coloured tracts descend from volcanic mountains to the valleys in frightful sterility, the chinks of their rugged masses scarcely affording sufficient water for the roots of mosses[415]. To the second class we refer compact limestone, a rock which contributes extensively to the formation of the solid crust of the globe. In so far as regards its principal constituent parts, it is not affected by atmospheric water or air; but, as its parts have but comparatively little cohesion, and are usually separated in a considerable degree by minute fissures, they are more liable to be broken down and crumbled by mechanical powers, than those of the rocks belonging to the first class. In districts where the fundamental rock is limestone, the layers of loose original soil or subsoil are thin, and filled with numerous fragments. As the soil arising from the disintegration of limestone contains a great proportion of calcareous matter, it is neither favourable to the growth of plants in general, nor to that of the greater number of vegetables which are the object of cultivation. Soil of this kind is too hot, dry and stony; hence the reason why districts, in which pure limestone rocks predominate, are often sterile. The case is different, however, where a portion of clay enters as an ingredient into the composition of calcareous rocks, for here the soil is usually very productive; or, where rocks of a different nature alternate with masses of pure limestone, having a greater capability than it of contributing to the formation of productive soil. When water, containing carbonic acid, passes through limestone rocks, it dissolves portions of it, and deposits them in other places, by which the decomposition of the limestone and the formation of loose earth may be in some measure accelerated.

To the third class belong chalk and gypsum; which, in so far as regards their decomposition by chemical means, are of a similar nature with compact limestone; but possessing a much slighter cohesion of parts, are more liable to be broken down by mechanical means. Water also dissolves gypsum, and thus assists in its disintegration. The soil arising from these rocks resembles that produced by compact limestone, which explains the want of fertility, observable in certain gypseous tracts of the North of Germany, and in the chalk districts of France. The fertility which we see in certain places where chalk is the fundamental rock, as in the Isle of Wight, Island of Rugen, &c. is to be attributed as well to argillaceous and marly strata alternating with the chalk, as to the greater humidity of the atmosphere, by which the dryness and heat of the soil are diminished.

In the fourth class we place certain rocks, composed of different minerals, but compact in appearance, which, although they resist mechanical disintegration, are yet subject to chemical action, and are, by means of it, converted into a loose, compound productive soil. Of this kind are basalt, and some other rocks very nearly allied to it.

To the fifth class we refer those rocks which have a crystalline, granular, or slaty texture. The mutual adhesion of the heterogeneous parts, of which they consist, being, in general, inconsiderable, they are easily broken down by mechanical means, and thus contribute in a high degree to the formation of productive soil. The felspar contained in these rocks, on account of the chemical decomposition which it readily undergoes, has a great effect not only upon the quantity, but also the fertility of the soil produced. The quartz, on the contrary, as well as the mica and hornblende, long resist chemical decomposition; they are, however, useful in this respect, that the argillaceous soil arising from the felspar, has its tenacity diminished; and is consequently rendered better adapted for vegetation, by being intermixed with them. Granite and gneiss, of all truly granular crystalline rocks, afford the deepest and most fertile soil, aptly compounded of different substances, sufficiently loose in its aggregation, and capable of retaining the necessary moisture. Soil arising from the disintegration of granite is unfavourable to vegetation only, where the rock abounds much in quartz, and where the superfluous water cannot run off, and so gives rise to marshes, which produce only vegetables of inferior quality; of which we have examples in the granite districts of Aberdeen. In such places as these, peat is easily generated, which, although of great use, is yet much less advantageous than wood. Syenite, which abounds much in hornblende, is inferior to granite, with respect to the production of fertile soil; and primitive greenstone, which resists disintegration and decomposition in the highest degree, occupies the last place in this class. In the series of slaty crystalline rocks, mica-slate is next to gneiss: but on account of the small proportion of felspar which enters into its composition, it does not afford so productive a soil.

In the sixth class may be placed the slaty rocks, whether simple, or intimately compounded, which do not readily undergo chemical decomposition, but which easily separate at their natural fissures, and are mechanically resolved into an earthy mass, forming a paste with water, circumstances which are observed chiefly in clay-slate, a rock of much importance in the formation of productive soil, usually passing into a clayey sort of earth.

To the seventh class belong the conglomerated rocks, whose parts indeed undergo very little, if any, chemical change, but are easily separated by mechanical means, and are thus converted into a gravelly, sandy, or earthy mass. Of this kind are greywacke, old red sandstone, and sandstones of various kinds. Much diversity is exhibited by these rocks, with regard to the facility with which they undergo disintegration, as well as the nature of the soil arising from them; circumstances which chiefly depend upon the nature of the cement, and its relation to the parts cemented. The disintegration of these rocks is the more easily effected that the cement is abundant, and less intimately connected with the other parts, that is, the more they depart from a crystalline nature; on which account greywacke is less easily converted into soil, than the common varieties of sandstone. By the decomposition of greywacke, a loose and fertile soil is formed, containing particles of quartz and clay in due proportion; on the other hand, by the decomposition of red sandstone, a soil is frequently produced, abounding in argillaceous particles impregnated with iron, and therefore stiff and cold. The variegated sandstone, with a marly cement, not unfrequently affords a pretty fertile soil; the quadersandstein, on the contrary, commonly presents a sandy and arid soil.

Lastly, in the eighth class we shall place those rocks, whether simple or intimately compounded, whose nature is so loose, or whose parts are so separated, that they fall with great facility into an earthy mass, and are also in part mechanically reduced by water. To this class belong the different varieties of marl, slate-clay, basaltic and volcanic tuffa. These rocks, many of which are extensively diffused, are of much importance in the formation of productive soil, although the quality of the earth produced by them varies much, according to their different natures. Slate-clay affords an argillaceous soil; in earth produced by the decomposition of marl, the clay is diminished in proportion to the greater abundance of the calcareous or sandy parts; while a mixed and very fertile soil is usually generated from basaltic and volcanic tufas.

The various relations which exist in the stratification and position of rocks, have much influence in producing a diversity in the soil formed immediately from their decomposition. This diversity cannot be so great when different rocks of various ages occur in a determinate order in horizontal strata; in which case, the uppermost bed may exhibit a great extent of surface of the same nature. When, on the other hand, strata of rocks of different natures, forms, and dimensions, placed at different angles of inclination, and in different directions, appear at the surface, it will easily be understood how it may happen that the soil produced by their decomposition may occur of very different qualities, in places not very distant from each other. The manner in which the soil is influenced by a difference in the arrangement and position of the strata, will become evident, on comparing districts in which one particular sort of rock lies beneath the surface in horizontal strata, with others in which the solid substratum is composed of various rocks differing in their inclination towards the horizon. In districts of the former kind, the qualities of the soil vary in general but little; in such as are of the latter kind, on the contrary, they are often found extremely different. The great diversity of soil seen in England, as well as in Germany, may, in fact, be partly explained by the circumstance, that, in those countries, the nature and position of the strata vary every where. On the other hand, the great similarity which pervades the soil of Southern Russia, is without doubt produced by a uniformity in the position and inclination of the limestone which lies immediately under the soil.

The nature of the principal mass of the strata usually exerts a great degree of influence over the qualities of the soil. When the solid substratum is sandstone, its effect upon the soil is, in general, as evidently seen, though not perhaps in an equal degree, as when it is marl. Exceptions, however, to this rule sometimes occur; as, for instance, when the principal mass of a rock which resists disintegration in a high degree contains beds that are easily reduced to earth. This is the case with the shell-limestone (muschelkalkstein) of Germany, the mountains of which are not unfrequently covered with a clayey soil, which has not been produced by the decomposition of the principal strata themselves, but by that of the slate-clay and argillaceous marl alternating with them.

Hitherto we have considered untransported soil, or that produced from the disintegration or decomposition of the subjacent rocks in the places where it occurs; we have now to examine the relations which exist between the subjacent rock, and the transported soil lying upon it. The nature of the rock does not indeed influence, excepting in a more remote degree, the transported soil, which has been carried to a greater or less distance from the places of its production, by the agency of moving powers, and again deposited of various forms and compositions. However, it may often be plainly seen, that the materials of this soil have been derived from particular rocks, and that these rocks have exerted some degree of influence over the formation and distribution of the transported soil. The examination of these relations is of great importance, because it is with secondary or transported soil that agriculture is principally concerned. The varieties of transported soil depend chiefly upon three circumstances: 1st, The nature of the rocks from which they are derived; 2dly, The quality and effect of the moving powers; 3dly, The changes which they may have undergone after their formation.

The origin of the materials which enter into the composition of transported soil, has been already considered. From their difference may be easily explained why soil generated from the debris of primitive crystalline rocks has different qualities from soil which has been derived from strata of sandstone or marl.

The principal powers which contribute to the transportation of soil, are, The weight of loose masses, ice, and water. The weight of loose masses is a cause of transportation which we frequently see in operation. By it the huge cones of debris at the base and upon the declivities of precipices and mountains, are gradually carried off toward the bottom of the valleys; a phenomenon which can scarcely any where be better seen than in the valleys of the Alps, where mountains sometimes occur evidently consisting of debris, and clothed with trees and shrubs, or covered with pastures, the masses of which are gradually moved, as upon inclined planes, by the action of the water which percolates through them.

Ice effects the transportation of rocks and debris, with a power which nothing can resist. This is no where more conspicuous than among the glaciers of the Alps, by the falling of which great heaps of stones and rubbish are produced. The transportation of large stones by means of ice may also be seen in our mountain torrents in winter. Huge masses of stone, scattered over the plains of the north of Germany and the islands of Denmark, and often very prejudicial to agriculture, whose northern origin appears to be established, may have been carried by the same powerful agent from Finland, Sweden and Norway, into those countries, at a time when the plains of northern Germany, with the other flat districts along the shores of the Baltic, were still covered by the waves of the ocean.

In the formation of transported soil, water usually exerts a great degree of power. By means of it, not only are vast masses transported to the greatest distances, but their parts are at the same time crumbled down and mingled together. To these operations are to be attributed the various terminations of different soils at horizontal distances, as well as the different alternations of their strata at vertical ones. The power of water in the formation of transported soil varies, not only according to the different inclinations of its channel, but also in regard to the form, size, and weight of the parts carried off by it; for which reason, in the formation of such soils, the same phenomena take place on a large scale, that we see on a smaller, in performing the operations of breaking and washing the ores of metals. For the same reason that, in these processes, the larger particles subside, while the smaller are propelled, from which again the heavier particles of ore are sooner deposited than the lighter; in plains in the vicinity of a mountain, covered with transported soil, stones and debris are usually seen first, then earth, clay, and sand mixed together, and farther on, finer sand, with strata of clay.

Transported or secondary soil, produced by water, according to the mode of its formation, is divided into four classes, viz.—1. Soil of Valleys; 2. River Soil; 3. Lake Soil; 4. Marine Soil.

1. Soil of Valleys.—It is washed down by rain and snow water, and partly also produced by rivulets, which carry off the loose parts from the declivities of mountains to the plains. The nature of this soil in general clearly shews the nearness of its origin. Its depth is always greatest in the bottom of the valley, and gradually diminishes toward the declivities of the mountains. The curvature of the different strata is usually accommodated to the irregularity of its external form, so that when a section is made of them, they exhibit a series of parallel curved lines.

2. River Soil, or the soil found in the beds and banks of rivers, and which is produced by the continual propelling power of large rivers. To this class belong two different kinds; 1st, Soil containing pebbles of various sizes, produced by the power of torrents in the vicinity of mountains; and, 2d, Earth or mud, deposited in the beds of rivers, in places at a distance from mountains. A peculiarity of river soil in general is, that it is much extended in length, while its breadth is comparatively but small. The different layers have neither so much irregularity as in the preceding kind, nor are they so precise in arrangement as in the following.

3. Lake Soil, deposited at the bottom of still water. To this class is to be referred the soil in the bottoms of valleys, which had formerly been lakes, either separate or connected with rivers. The horizontal dimensions of this kind of soil are often more or less equal. Sometimes, indeed, the length is greater than the breadth; not, however, in the same degree as in soil deposited in the bed of rivers. The surface is usually plane, and the different strata alternate in a parallel manner.

4. Marine Soil, that is to say, the mud of the ancient ocean. It is the greatest of all in its extent, both in a horizontal and a vertical direction. Its surface is more or less undulated, very seldom even. Its masses are both very thick and very uniform in composition. Different and alternating strata, however, do occur, whose forms and dimensions are usually more or less regular, and which are not unfrequently undulated.

Soil, after being formed, is acted upon by natural powers in various ways. The atmosphere is perpetually modifying it; rivers, waves, and winds, act here and there upon its surface, and alter its external form; water introduces into it the substances which it holds in solution. The different constituent parts of soil act upon each other chemically, and in this manner new decompositions and mixtures are produced; and this chemical change is increased by the action of vegetables, as well as of bodies deriving their origin from both organic kingdoms.

From what has been said of the relations existing between the masses of which the solid crust of the globe is composed, and the loose earth or soil by which it is covered, it appears evident enough (Hausmann concludes) that they have great influence over its formation and nature, and therefore upon the more perfect vegetables, and especially those which are the objects of cultivation; and that although the fertility of the soil is much increased by these vegetables themselves, yet the first foundation of their vigour is derived from the disintegration and decomposition of rocks. If this be correct, the constitution of the solid crust of the earth has a much more extended influence. For, by preparing a habitation for the greater and most important parts of plants, it also exerts a high degree of influence upon the animals which derive their sustenance from them, and, at the same time, affords the means of subsistence to man[416].

NOTE.

ACCOUNT OF THE IRISH ELK, FOSSIL ELEPHANT OR MAMMOTH, AND THE MASTODON.

As the Irish Elk, the Fossil Elephant or Mammoth, and the Mastodon, are among the most remarkable of the fossil and extinct species of quadrupeds mentioned in the preceding pages of this work, we, with the view of farther gratifying the curiosity of our readers, now lay before them the following additional details from the writings of Cuvier, Goldfuss, and others.

1. Fossil Elk of Ireland, Cervus megaceros[417].

(Noticed at p. 286.)

One of the most magnificent of the bisulcated animals met with in a fossil state in the British Islands is the Elk of Ireland, the Cervus megaceros. Bones and horns of vast size of this species are almost daily dug out of the bogs and marl pits of Ireland. Similar remains have been met with in alluvial strata in Britain, and also in the Isle of Man.

“So frequently do these remains,” Mr Hart remarks, “occur in most parts of Ireland, that there are very few of the peasantry who are not, either from personal observation or report, acquainted with them by the familiar name of the horns of the ‘old deer.’ Indeed in some parts of the country they have been found so often, that far from being regarded as objects of any extraordinary interest, they have been either thrown aside as lumber, or applied to the commonest economical uses[418].

“I have made diligent but fruitless search for an account of the particular time when any of these remains were first discovered. As they generally occur in marl, it is most likely that they did not begin to attract attention until the advanced state of agriculture had created an increased demand for that mineral as a manure. We can very easily imagine the astonishment which the appearance of horns so large, and of such strange form, must have excited in the minds of those who discovered them for the first time, and how readily they obtained a place in the hall of some adjoining mansion, where they were deposited as an ornament of great curiosity, from the contrast which they formed with the horns of the species of deer known at present. In this way we may account for the preservation of so many specimens as are found in the possession of the gentry in different parts of this country.

“Very lately an entire skeleton of the Irish Elk was dug up in that country. The following statement of the circumstances under which the bones were found, with their geological position, was laid before the Dublin Society, in a letter from Archdean Maunsell to the Right Hon. George Knox.

Middleton Lodge, March 8. 1825.

“MY DEAR SIR,

“I deferred replying to your letter of the 1st, as it was my intention to proceed to Limerick in a few days, and I was anxious to look over some notes I had taken, and which I left there, of the circumstances connected with the discovery of the fossil remains which the Royal Dublin Society have received. As I have, however, been obliged to postpone my departure for several days, I can no longer defer offering my best thanks for the kind manner in which you have received the conjectures which I formed upon a subject to which my attention was directed, by having fortunately been present before the bones were disturbed from the situation in which they had lain during a period which I apprehend it would not be easy to define. I am sensible that any consideration which may have been attached to my observations should be attributed to the interest which the subject itself is calculated to excite, rather than to any ability of mine to do it justice. The opinion which I took the liberty of communicating to you was formed after some consideration, and although I had not the most remote idea of its being worthy of any attention, I can have no objection to your making any use of it which you may conceive expedient. There is, I conceive, much interesting material for speculation, resulting from the discovery of these fossil remains, and the first that naturally occurs is the manner in which the animals were destroyed, and the bones so singularly preserved. I stated, in the hasty sketch which I gave you of my theory upon this point, that I apprehended they must have been destroyed by some overwhelming deluge, that they were probably drowned upon the hills where they had taken refuge, as the waters rose, and that, as they subsided, they were drawn from thence into the valley in which they were found; that the agitation of the waters had occasioned such a dispersion of the bones, when the ligaments dissolved, as would account for their having been scattered in the way in which they were found, and that the deposite of shell marl, with which I supposed the water to have been turbid, had so completely protected them from atmospheric influence as to prevent their subsequent decomposition. To enable you to form some estimate of the reasonableness of this supposition, it is necessary that I should endeavour to explain the situation, &c. of the valley and the adjoining hills. The valley in which the remains were found contains about twenty plantation acres, and the soil consists of a stratum of peat about a foot thick, immediately under this a stratum of shell-marl, varying from 1½ to 2½ feet in thickness; in this many of the shells retain their original colour and figure, and are not marine; under the marl there is a bed of light blue clay; through this one of my workmen drove an iron rod, in several places, twelve feet deep, without meeting opposition. Most of the bones and heads, eight in number, were found in the marl; many of them, however, appeared to rest on the clay, and to be merely covered by the marl. The remains were disposed in such a manner as to prevent the possibility of ascertaining the exact component parts of each skeleton; in some places portions were found removed many yards from others, and in no instance were two bones found lying close to each other. Their position also was singular; in one place two heads were found, with the antlers entwined in each other, and immediately under them a large blade-bone; in another, a very large head was discovered, and although a most diligent search was made, no part of the skeleton found; within some hundred yards, in another, the jaw-bones were found, and not the head. The conclusion which, I conceive, may fairly be deduced from such a position of the various parts of the animals is, that there must have been some powerful agent employed in dispersing them after their death; and as I consider it impossible that their own gravity could have been sufficient to sink them through the various strata, I conceive these must have originated subsequently to the dispersion of the bones. I also think, that, if they had been exposed for any time to atmospheric influence, they never could have been preserved in their present extraordinary perfection.

“The hills immediately adjoining this valley are composed of limestone, with a covering of rich mould of various degrees of thickness. One of them, whose base is about thirty acres, rises directly from the edge of the valley, with sides very precipitous, and in one place perfectly perpendicular, of naked limestone. In every part of this hill the superficies comprises as much stone as mould; on the side nearly opposite, the hill is equally high, but the sides not so steep, and the covering of mould thicker; on the other sides the ground only rises in some degree (twenty or thirty feet perhaps), and consists of a thin mould, and immediately under a very hard limestone gravel. Indeed, except where limestone forms the substratum, this is the character of all the soil in the vicinity except the Corkasses, which are evidently alluvial. I am fully aware, that, assuming the destruction of the animals to have been occasioned by a flood, they would naturally have retreated from the water to the hills, and that, as they probably met their fate there, their remains should have been discovered on the summit of the hills, and not in the valley, particularly as one of them is perfectly flat on the top, which contains six or seven acres. I apprehend that the remains of many of them were deposited on the tops of the hills; but as they have now only a slight covering of mould, not sufficient to cover a small dog, they were formerly perfectly bare; and as they were thus devoid of the means of protecting the remains from the atmosphere, whatever was left there soon became decomposed, and resolved into portions of the mould, which is now to be found on the hills. This remark I conceive also to be applicable to the soil with the substratum of limestone gravel, which affords quite as little material for preserving the bones as the hills do.

“It is material that I should observe, that of eight heads which we found, none were without antlers; the variety in character also was such as to induce me to imagine, that possibly the females were not devoid of these appendages. Unfortunately, however, from the difficulty of raising them, being saturated with water, and as soft as wet brown paper, only three were at all perfect.

“Having now disposed of these antediluvians, a question naturally arises, how it happens that the fossil remains of no other animals were found, when the same fate probably overwhelmed every existing creature? Could deer have been the only living beings at that period? Was Ireland part of a great continent when this catastrophe occurred, and were these unfortunates the first emigrants to our Isle from that great centre from whence the globe was supplied with occupants, and did they perish before other animals less influenced by enterprise, and less endowed with physical strength, could have followed their example? These problems I confess myself unable to solve, and shall not presume to obtrude my many reveries upon this and other points, which have originated in the discovery of a few bones, upon those who I know are so much better competent to form a sound opinion. I shall, I hope, be able to send the antlers, which are very fine, on the 15th of this month.

“If you have a desire to make any use of this letter, I can only say I have no objection. I remain, dear Sir, with feelings of great respect,

“Yours most truly,

William W. Maunsell.”

Of this skeleton, the most perfect hitherto found, the following interesting description is given by Mr Hart, in his memoir.

“This magnificent skeleton is perfect in every single bone of the framework which contributes to form a part of its general outline: the spine, the chest, the pelvis, and the extremities, are all complete in this respect; and, when surmounted by the head, and beautifully expanded antlers, which extend out to a distance of nearly six feet on either side, forms a splendid display of the reliques of the former grandeur of the animal kingdom, and carries back the imagination to a period when whole herds of this noble animal wandered at large over the face of the country.

To proceed with a description of the several parts of this specimen in detail, I shall commence with the horns, which give the animal its chief characteristic feature.

The horns.—That the description of these may be the more intelligible, I will first explain the terms which I mean to apply to their several parts. Each horn consists of the socket or root, the burr or coronary circle, the beam or shaft, the palm and the antlers.

The socket or root is the part of the horn which grows out of the frontal bone, and which is never shed; it is smooth, of a brown colour, an inch and half in length, and eleven inches three quarters in circumference; in the animal’s lifetime it was covered by the skin. The coronary or bead-like circle, or burr, is a ring of small, hard, whitish prominences, resembling a string of pearls, which encircles the junction of the socket with the part of the horn which falls annually from the heads of all deer.

The beam or shaft extends outwards, with a curvature whose concavity looks downwards, and backwards. This part is nearly cylindrical at its root, and its length equals about one-fourth of that of the whole horn; its outer end is spread out and flattened on its upper surface, and is continuous with the palm, which expands outwards in a fan-like form, the outer extremity of which measures two feet ten inches across, being its broadest part. Where the beam joins the palm the horn undergoes a kind of twist, the effect of which on the palm is, to place its edges above and below, and its surfaces anterior and posterior; the anterior surface is convex, and looks outwards; the posterior is concave, and its surface looks towards that of the opposite palm. Such is the position of the horns, when the head is so placed that the zygomatic arch is parallel to the horizon, as it would be during progression, or whilst the animal stands in an easy posture.

The antlers are the long pointed processes which project from the horns, two of which grow from the beam anteriorly; the first comes off immediately from the root, and is directed downwards, overhanging the orbit; this is called the brow antler, which, in this specimen, is divided into two points at its extremity[419].

The other antler, which comes off from the beam, we may call the sur-antler: in this specimen it consists of a broad plate or palm, concave on its upper surface, horizontal in its direction, and forked into two points anteriorly,—an appearance which I have not observed in any other specimen of upwards of forty which I have seen, nor do I find it marked in any of the plates of those bones extant.

There is one antler given off posteriorly from the junction of the beam with the palm: it runs directly backwards parallel to the corresponding one of the opposite horn. The inferior edge of the palm beyond this runs outwards and backwards: it is obtuse and thick, and its length is two feet six inches. From the anterior and external borders of each palm there come off six long pointed antlers. None of these are designated by any particular name. The number of the antlers of both sides taken together is twenty-two.

The surface of the horns is of a lightish colour, resembling that of the marl in which they were found; they are rough, and marked with several arborescent grooves, where the ramifications of the arteries by which they had been nourished during their growing state were lodged. The horns, with the head attached, weighed eighty-seven pounds avoirdupois. The distance between their extreme tips in a right line is nine feet two inches.

Head.—The forehead is marked by a raised ridge extended between the roots of the horns; anterior to this, between the orbits and the root of the nose, the skull is flat; there is a depression on each side in front of the root of the horn and over the orbit, capable of lodging the last joint of the thumb, at the bottom of which is the superciliary hole, large enough to give passage to an artery proportioned to the size of the horns. Inferior to the orbit we have the lachrymatory fossa, and the opening left by the deficiency of bone common to all deer, and remarkable for being smaller in this than in any other species.

Below the orbits the skull grows suddenly narrower, and the upper parts of the nasal bones become contracted by a depression on either side, at the lower part of which is the infra-orbitar hole. The opening of the nares is oval, being five inches long by three broad, the greatest breadth being in the centre. From the roots of the horns to the occipital spine measures three inches and an half; the occiput descends at a right angle with this, being three inches deep to the foramen magnum: the greatest breadth of the occiput is eight inches. The temporal fossÆ approach to within two inches of each other behind the horns.

Teeth.—They do not differ from those of animals of the ruminating class. The incisors were not found, having dropped out; there is no mark of canine teeth; the molares are not much worn down, and are twenty-four in number.

The skeleton measures, from the end of the nose to the tip of the tail, ten feet ten inches. The spine consists of twenty-six vertebrÆ, viz. seven cervical, thirteen dorsal, and six lumbar. The size of the cervical vertebrÆ greatly exceeds that of the other classes, and the spines of the dorsal rise to a foot in height. The necessity of these bones being so marked is obvious, considering the strong cervical ligament, and powerful muscles, required for supporting and moving a head which, at a moderate calculation, must have sustained a weight of three quarters of a hundred of solid bony matter.

The extremities are in proportion to the different parts of the trunk, and present a conformation favourable to a combination of great strength with fleetness.

It is not the least remarkable circumstance connected with these bones, that they are in such a high state of preservation as to present all the lines and impressions of the parts which had been attached to them in the recent state. Indeed, if we examine them as compared with the bones of an animal from which all the softer parts have been separated by maceration, the only perceptible differences in their physical properties are, that they are a little heavier, a degree harder, that their surface is brown, and that they all, with the exception of the horns, present a polished appearance, which is owing to the periosteum having been preserved, and still remaining to cover them, as was discovered when they were chemically examined.

The existence of fat or adipocire in the shaft of one of the bones mentioned by Archdeacon Maunsell, and which I saw in his possession, is a thing for which it is extremely difficult to account, as it occurred but in one solitary instance, and it did not appear that this bone was at all differently circumstanced from the rest. Those which I had an opportunity of examining, by boring holes in them, were hollow, and contained, for the most part, only a small quantity of black animal earth.

Mr Stokes found, in a rib of this animal,

Animal matter, 42.87
Phosphates with some Fluates, 43.45
Carb., Lime 9.14
Oxides, 1.02
Silica, 1.14
Water and loss, 2.38
———
100.00

Dr Apjohn of Dublin made the following observations with regard to the animal matter in the bones:

‘The bone was subjected for two days to the action of dilute muriatic acid. When examined at the end of this period, it had become as flexible as a recent bone submitted to the action of the same solvent. The periosteum was in some parts puffed out by carbonic acid gas, disengaged from the bone, and appeared to be in a state of perfect soundness.

‘To a portion of the solution of the bone in the muriatic acid some infusion of galls was added, which caused a copious precipitate of a dun colour. This proved to be tannate of gelatine, mixed with a small portion of the tannate and gallate of iron.

‘The cartilage and gelatine, therefore, so far from being destroyed, had not been perceptibly altered by time.’”

Until Baron Cuvier published his account of these remains[420], they were generally believed to have belonged to the same species as the moose deer or elk of North America, an opinion which appears to have been first advanced by Dr Thomas Molyneux in 1697[421], and which depends principally on the exaggerated description of that animal given by Josselyn in his account of two voyages to New England, published in 1674, in which he states that it is sometimes twelve feet high, with horns of two fathoms wide! This was the more readily believed by the learned Doctor, as it tended to confirm him in a favourite theory which he seems to have entertained, that Ireland had once been joined to the New Continent.

But the assertions of Josselyn regarding the size of the American moose have not been confirmed by the testimony of later travellers, from whose observations it is now clearly ascertained that the only large species of deer inhabiting the northern parts of America are the wapiti or Canadian stag (Cervus canadensis), the rein-deer (C. Tarandus), and the moose or elk (C. Alces).

The peculiar branching of the brow antlers of the rein-deer, and the rounded horns of the wapiti[422], are characters sufficient to prevent us confounding either of these animals with the fossil species.

The palmate form of the horns of the elk gave greater probability to the opinion of its specific identity with the fossil animal.

A little attention, however, to a few circumstances, will shew a most marked difference between them.

First, as to size, the difference is very remarkable, it not being uncommon to find the fossil horns ten feet between the extreme tips[423], while the largest elk’s horns never measure four feet. This measurement in a pair in the Museum of the Royal Dublin Society, is three feet seven inches: the largest pair seen by Pennant in the house of the Hudson’s Bay Company, measured thirty-four inches[424].

The horn of the elk has two palms, a lesser one which grows forward from the front of the beam, where the principal palm begins to expand. This is called brow antler by Cuvier, but it corresponds in situation rather to the sur-antler, there being, properly speaking, no brow antler attached to the root of the beam. The elk has no posterior antler similar to that of the fossil animal, nor does its beam take a similar arched direction, but runs more directly outwards.

Cuvier remarks, that the palm of the fossil horn increases in breadth as it extends outwardly, while that of the elk is broadest next the beam.

The palm of the elk’s horn is directed more backwards, while the fossil one extends more in the lateral direction. The antlers of the elk are shorter and more numerous than those of the fossil animals.

As the horns of the fossil animal exceed in size those of the elk, so, on the contrary, does the skull of the latter exceed in size that of the former; the largest heads of the fossil species not exceeding one foot nine inches in length, while the head of the elk is frequently two feet. The fossil head is broader in proportion; its length being to its breadth as two to one; in the elk they are as three to one, according to Parkinson.[425] The breadth of the skull between the roots of the horns is but four inches in the fossil skulls; in that of the elk in the Society’s Museum it is 6½ inches.

Cuvier thinks it probable that the females of the fossil species had horns[426], an opinion to which I am very much disposed to subscribe, from having observed that these parts present differences in size and strength, which appear not to be dependent on differences of age. For instance, the teeth of the specimen in Trinity College are much more worn down, and the sutures of the skull are more effaced than in the specimen described in this paper; yet the horns of the latter are much more concave, and more expanded, than those of the former; and on comparing a single horn of each of these specimens together, that belonging to the Society exceeds the other by nearly a sixth in the length, and little less than a third in the breadth; it is not, therefore, unlikely that the animal whose horns were larger and more curved was a male. Something similar to this is observed in the rein-deer, both sexes of which have horns, but with this difference, that they are smaller and less branched in the female. Hence we find that this animal possessed characters of its own sufficient to prove it of a species as distinct from the moose or elk as this latter species is from the rein-deer or any other. Therefore, it is improper to retain the name of elk or moose deer any longer: perhaps it might be better called the Cervus megaceros, a name merely expressive of the great size of its horns.

That this animal shed its head furniture periodically, is proved by the occasional occurrence of detached horns having the smooth convex surface below the burr, similar to what is observed on the cast horns of all deer. Specimens of this are to be seen in the Museum of Trinity College, and I possess one myself, of which I have had a drawing made. As every other species of deer shed their horns annually, there is no reason for supposing that that process occurred at longer intervals in this.

It is a popular opinion with the Indians that the elk is subject to epilepsy, with which he is frequently seized when pursued, and thus rendered an easy prey to the hunters. Many naturalists affect to disbelieve this account, without, however, assigning any sufficient reason. But if it be considered, that, during the growth of the horns, there must be a great increased determination of blood to those parts, which are supplied by the frontal artery, a branch from the internal carotid, it is quite conformable to well established pathological principles, to suppose, that, after the horns are perfected, and have ceased to receive any more blood, that fluid may be determined to those internal branches of the carotid which supply the brain, and establish a predisposition to such derangements of its circulation as would produce epilepsy, or even apoplexy: if such an effect were produced in consequence of the size of the horns in the elk, it is reasonable to suppose that it prevailed in a greater degree in the fossil animal whose horns were so much larger.

What could have been the use of these immense horns? It is quite evident that they would prevent the animal making any progress through a thickly wooded country, and that the long, tapering, pointed antlers were totally unfit for lopping off the branches of trees, a use to which the elk sometimes applies his horns[427], and for which they seem well calculated, by having their antlers short and strong, and set along the edge of the palm, somewhat resembling the teeth of a saw in their arrangement. It would rather appear, then, that they were given the animal as weapons for its protection, a purpose for which they seem to have been admirably designed; for their lateral expansion is such, that should occasion require the animal to use them in his defence, their extreme tips would easily reach beyond the remotest parts of his body; and if we consider the powerful muscles for moving the head, whose attachments occupied the extensive surfaces of the cervical vertebrÆ, with the length of the lever afforded by the horns themselves, we can easily conceive how he could wield them with a force and velocity which would deal destruction to any enemy having the hardihood to venture within their range.

From the formidable appearance of these horns, then, we must suppose that their possessor was obnoxious to the aggressions of some carnivorous animals of ferocious habits; and such we know to have abounded in Ireland, as the wolf, and the celebrated Irish wolf dog. Nor would it be surprising if limestone caves should be discovered in this country, containing the remains of beasts of prey and their victims, similar to the hyÆnas’ dens of Kirkdale, and other places, respecting which such interesting researches have been lately laid before the public by the geologists of this country and the Continent.

The absence of all record, or even tradition, respecting this animal[428], naturally leads one to inquire whether man inhabited this country during its existence? I think there is presumptive evidence in the affirmative of this question, afforded by the following circumstances. A head of this animal described by Professor Goldfuss of Bonn, was discovered in Germany in the same drain with several urns and stone hatchets; and in the 7th volume of the ArchÆologia Britannica, is a letter of the Countess of Moira, giving an account of a human body found in gravel, under eleven feet of peat soaked in the bog water: it was in good preservation, and completely clothed in antique garments of hair, which her ladyship thinks might have been that of our fossil animal. But more conclusive evidence on this question is derived from the appearance exhibited by a rib, presented by Archdeacon Maunsell to the Royal Dublin Society, in which I discovered an oval opening near its lower edge, the long diameter of which is parallel to the length of the rib, its margin is depressed on the outer, and raised on the inner surface, round which there is an irregular effusion of callus. This opening had been evidently produced by a sharp pointed instrument, which did not penetrate so deep as to cause the animal’s death, but which remained fixed in the opening for some length of time afterward; in fact it was such an effect as would be produced by the head of an arrow remaining in a wound after the shaft was broken off[429].

It is not improbable, therefore, that the chace of this gigantic animal once supplied the inhabitants of this country with food and clothing.

As to the causes which led to the extinction of this animal, whether it was suddenly destroyed by the deluge, or by some other great catastrophe of nature, or whether it was ultimately exterminated by the continued and successful persecution of its pursuers, as has nearly been the case with the red deer within the recollection of many of the present generation, I profess myself unable to form any decided opinion, owing to the limited number of facts as yet collected on the subject. On some future occasion I may, perhaps, be induced to revert to so interesting a topic, should I have opportunities of discovering any thing worthy of communication.

The following Table exhibits a comparative view of the measurements of different parts of the skeletons of the Cervus Megaceros in the Museum of the Royal Dublin Society, and in the Royal Museum of the University of Edinburgh, with some parts of the Moose. The measurements of the Edinburgh specimen are taken from Professor Jameson’s memoir on organic remains, in the Supplement to the Encyclopedia Britannica.

HEAD. R. D. Soc. U. of Edin. Moose
Ft. In. Ft. In. Ft. In.
Length of the head, 1 1
Breadth of the skull between the orbits. 0 10½ 0 9
Do. of skull at the occiput, 0 8
Diameter of the orbit, 0 2? 0
Distance between infra orbitar holes across the skull, 0 7
Length of alveolar processes of the upper jaw, 0 6 0 6
Length of lower jaw, 1 0
Diam. of foramen magnum, 0 2
HORNS.
Distance between the extreme tips, measured by the skull, 11 10
Ditto, in a straight line across, 9 2 6 8 3 7
Length of each horn, 5 9 5 1
Greatest breadth of the palm, 2 10
Length of the beam, 1 9 0
Ditto of brow antler, 0
Ditto of sur-antler, 1 4
Circumference of the beam at root of brow antler, 1 0
BODY.
Length of spine, 10 10 9 8
Ditto of sternum, 2 4
Height to the upper extremity of the dorsal spines, 6 6
Ditto to the highest point of the tip of the horn, 10 4
EXTREMITIES.
Greatest length of the scapula, 1
Ditto breadth at the base, 0 10¾
Ditto depth of its spine, 0
Length of the humerus, 1 4 1
Ditto of ulna and radius, 1 8 1 6
Ditto of carpus, 0 0 2
Circumference of do., 0
Length of metacarpus, 1 1
Length of phalanges, 0 7 0
From anterior superior spine of one ileum to that of the other, 1 1
From anterior superior spine to the tuber ischii, 1 8 1
Greatest diameter of foramen ovale, 0 4 0 3
Least do. of do., 0 0
Length of the femur, 1 1
Ditto of tibia, 1 6 1 6
Length of the tarsus, including the os calcis, 0 8
Ditto of the metatarsus, 1 1

2. Account of the Two Living Species of Elephant, and of the Extinct Species of Elephant, or Mammoth.

1. Elephas africanus.The Elephant with rounded skull, large ears, grinders, having rhomboidal-shaped marks on their crown, which we call the African Elephant (Elephas Africanus), is a quadruped which has hitherto been found only inhabiting Africa. There can be no doubt that it is this species which lives at the Cape, at Senegal, and in Guinea; there is reason to believe that it also occurs at Mosambique; but it is not certain that individuals of the following species do not occur in this part of Africa. A sufficient number of individuals have not been figured or compared, to know if this species presents remarkable varieties. It is it that produces the largest tusks. Both sexes are equally furnished with tusks, at least at Senegal. The natural number of the hoofs is four before, and three behind. The ear is very large, and covers the shoulder. The skin is of a deep and uniform brown. This species has not been domesticated in modern times. It appears, however, to have been tamed by the ancients, who attributed to it less power and courage in that state than to the following species; but their observations do not appear to have been confirmed, at least in so far as refers to magnitude. Its natural manners are not perfectly known; yet judging of them by the notices of travellers, they appear to resemble in every thing essential those of the following species.

2. Elephas indicus.The Elephant with elongated skull, concave forehead, small ears, grinders marked with undulating bands, which we call the Indian Elephant (Elephas Indicus), is a quadruped which has only been observed with certainty beyond the Indus. It extends from both sides of the Ganges to the Eastern Sea and the south of China. They are also found in the Islands of the Indian Sea, in Ceylon, Java, Borneo, Sumatra, &c. There is still no authentic proof that it exists in any part of Africa, although neither is the contrary absolutely proved. The inhabitants of India having from time immemorial been in the habit of taking this species and taming it, it has been much better observed than the other. Varieties have been remarked as to size, lightness of form, the length and direction of the tusks, and the colours of the skin. The females and some of the males have tusks which are always small and straight. The tusks of the other males never attain so great a length as in the African species[430]. The natural number of the hoofs is five before and four behind. The ear is small, frequently angular. The skin is commonly grey, spotted with brown. There are individuals entirely white. The height varies from fifteen to sixteen feet. Its manners, the mode of taking it, and of treating it, have been carefully described by many travellers and naturalists, from Aristotle down to Mr Corse Scott.

3. Elephas primigenius, Blum, or Mammoth.—The Elephant with elongated skull, concave forehead, very long alveolÆ for the tusks, the lower jaw obtuse, the grinders broader, parallel, marked with closer bands, which we name the Fossil Elephant (Elephas primigenius, Blum.), is the Mammoth of the Russians. Its bones are only found in the fossil state. No person has seen in a fresh state bones resembling those by which this species is peculiarly distinguished, nor have the bones of the two preceding species been seen in the fossil state.[431] Its bones are found in great number in many countries, but in better preservation in the north than elsewhere. It resembles the Indian more than the African species. It differs, however, from the former in the grinders, in the form of the lower jaw, and many other bones, but especially in the length of the alveolÆ and tusks. This last character must have singularly modified the figure and organisation of its proboscis, and given it a physiognomy much more different from that of the Indian species, than might have been expected from the similarity of the rest of their bones. It appears that its tusks were generally large, frequently more or less spirally arcuate, and directed outwards. There is no proof that they differ much according to differences of sex or race. The size was not much greater than that to which the Indian species may attain; it appears to have been still clumsier in its proportions. It is already manifest from its osseous remains, that it was a species differing more from the Indian, than the ass from the horse, and the jackal and isatis from the wolf and fox. It is not known what had been the size of its ears, or the colour of its skin; but it is certain that, at least, some individuals bore two sorts of hair, namely, a red, coarse, tufted wool, and stiff black hairs, which, upon the neck and along the dorsal spine, became long enough to form a sort of mane. Thus, not only is there nothing impossible in its having been able to support a climate which would destroy the Indian species, but it is even probable that it was so constituted as to prefer cold climates. Its bones are generally found in the alluvial and superficial strata of the earth, and most commonly in the deposits which fill up the bottom of valleys, or which border the beds of rivers. They scarcely ever occur by themselves, but are confusedly mingled with bones of other quadrupeds of known genera, such as rhinoceroses, oxen, antelopes, horses, and frequently with remains of marine animals, particularly conchiferous species, some of which have even been found adhering to them. The positive testimony of Pallas, Fortis, and many others, does not allow us to doubt that this latter circumstance has frequently taken place, although it is not always observed. We ourselves have at this moment under our eyes a portion of a jaw covered with millepores and small oysters.

The strata which cover the bones of elephants are not of very great thickness, and they are scarcely ever of a rocky nature. They are seldom petrified, and there are only one or two cases recorded in which they were found imbedded in a shelly or other rock. Frequently they are simply accompanied with our common fresh water shells. The resemblance, in this latter respect, as well as with regard to the nature of the soil, between the three places, of which we have the most detailed accounts, viz. Tonna, Cantstadt, and the Forest of Bondi, is very remarkable. Every thing, therefore, seems to announce that the cause which has buried them, is one of the most recent of those that have contributed to change the surface of the globe. It is nevertheless a physical and general cause; the bones of fossil elephants are so numerous, and have been found in places so desert and even uninhabitable, that we cannot suppose that they had been conducted there by man. The strata which contain them and those which are above them, shew, that this cause was aqueous, or that it was water that covered them; and in many places these waters were nearly the same as those of our present sea, since they supported animals nearly the same. But, it was not by these waters that they were transported to the places where they now are. Bones of this description have been found in almost every country that has been examined by naturalists. An irruption of the sea that might have brought them from places which the Indian elephant now inhabits, could not have scattered them so far, nor dispersed them so equably. Besides, the inundation which buried them has not risen above the great chains of mountains, since the strata which it has deposited, and which cover the bones, are only found in plains of little elevation. It is not, therefore, seen how the carcases of elephants could have been transported into the north, across the mountains of Thibet, and the Altaic and Uralian chains.

Further, these bones are not rolled; they retain their ridges and apophyses; they have not been worn by friction. Very frequently the epiphyses of those which had not yet attained their full growth, are still attached to them, although the slightest effort would suffice to detach them. The only alterations that are remarked, arise from the decomposition which they have undergone during their abode in the earth. Nor can it with more reason be represented that the entire carcases had been violently transported. In this case, the bones would indeed have remained entire; but they would also have remained together, and would not have been scattered. The shells, millepores, and other marine productions which are attached to some of these bones, prove besides that they had remained at least some time stripped and separated at the bottom of the fluid which covered them. The elephants’ bones had therefore already been in the places in which they are found, when the fluid covered them. They were scattered about in the same manner as in our own country the bones of horses and other animals that inhabit it may be, and as the dead bodies are spread in the fields.

Every circumstance, therefore, renders it extremely probable, that the elephants which have furnished the fossil bones, dwelt and lived in the countries where their bones are at present found. They could only, therefore, have disappeared by a revolution, which had destroyed all the individuals then living, or by a change of climate, which prevented them from propagating. But whatever this cause may have been, it must have been sudden. The bones and ivory which are found in so perfect a state of preservation in the plains of Siberia, are only so preserved by the cold which congeals them there, or which, in general, arrests the action of the elements upon them. If this cold had come on by degrees and slowly, these bones, and still more the soft parts with which they are still sometimes invested, would have had time to decompose, like those which occur in warm and temperate countries. It would especially have been impossible that an entire carcase, like that discovered by Mr Adams, could have retained its flesh and skin without corruption, if it had not been immediately enveloped by the ice which preserved it. Thus, all the hypotheses of a gradual cooling of the earth, or of a slow variation, whether in the inclination or in the position of the axis of the globe, fall to be rejected.

If the present elephants of India were the descendants of these ancient elephants, which have been preserved in that climate to the present day, from their being there placed beyond the reach of the catastrophe which destroyed them in the others, it would be impossible to explain why their species has been destroyed in America, where remains are still found, which prove that they had formerly existed there. The vast empire of Mexico presented to them heights enough to escape from an inundation so little elevated as that which we must suppose to have taken place, and the climate there is warmer than is requisite for their temperament.

The various mastodons, the hippopotamus and the fossil rhinoceros lived in the same countries, and in the same districts, as the elephants, since their bones are found in the same strata and in the same state. Yet these animals very assuredly no longer exist. Every thing therefore, Cuvier maintains, concurs to induce a belief that the fossil elephant is, like them, an extinct species, although it resembles more than they one of the species at present existing, and that its extinction has been produced by a sudden cause, by the same great catastrophe which destroyed the species of the same epoch.

3. On the Great Mastodon, or Animal of the Ohio.

It appears that the Great Mastodon or Animal of the Ohio, was very like the elephant in its tusks and whole skeleton, the grinders excepted; that it very probably had a proboscis; that its height did not exceed that of the elephant, but that it was a little more elongated, and had limbs somewhat thicker, with a more slender belly. Notwithstanding all these points of resemblance, the peculiar structure of its grinders is sufficient to constitute it of a different genus from the elephant. It further appears, that it fed much in the same manner as the hippopotamus and boar, choosing by preference the roots and other fleshy parts of vegetables; that this sort of food must have drawn it towards the soft and marshy places; that, nevertheless, it was not formed for swimming, and living often in the water like the hippopotamus, but that it was a true land animal. Its bones are much more common in North America than any where else. They are even perhaps exclusively confined to that country. They are better preserved, and fresher, than any other fossil bones known; and, nevertheless, there is not the slightest proof, the smallest authentic testimony, calculated to impress a belief that either in America, or any where else, there is still any living individual, for the various accounts which we have from time to time read in the journals respecting living mastodons, which had been observed in the forests or plains of that vast continent, have never been confirmed, and can only pass for fables.

Note

ON THE CAVES IN WHICH BONES OF CARNIVOROUS ANIMALS OCCUR IN GREAT QUANTITIES.

The extraordinary accumulations of fossil bones in caves and caverns in different districts, especially in those composed of limestone, have for many years engaged the attention of inquirers; and, of late, have afforded many interesting facts to the geologist and zoologist. In England, as will appear from the following details, many different fossil animals have been discovered in limestone caves; but hitherto the caves in Scotland, which will probably be found to contain interesting documents of an ancient population, have not been examined. As the subject is a curious and interesting one, we shall, in the following pages, principally from Cuvier’s great work, lay before our readers a pretty full account of the different caves, especially those that afford bones of carnivorous animals.


Numerous caves, brilliantly decorated with stalactites of every form, succeeding each other to a great depth in the interior of mountains, communicating together by openings so narrow as scarcely to allow a man to enter them crawling, and which are yet found strewed with an enormous quantity of bones of large and small animals, are without dispute among the most remarkable phenomena which the history of fossil remains could present to the contemplation of the geologist, especially when we reflect that this phenomenon recurs in a great number of places, and over a very extended space of country. These caves have been the object of research of several naturalists, some of whom have well described and figured the bones which they contain; and even before they were explored by the naturalist, they were celebrated among the common people, who, according to their custom, added many imaginary prodigies to the natural wonders which are really observed in them. The bones which they contain were long, under the name of fossil unicorn, an important article of commerce and materia medica, on account of the powerful virtues which were attributed to them; and it is probable that the desire of finding these bones contributed much to the more accurate knowledge of these caves, and even to the discovery of several of them.

The most anciently celebrated is the cave of Bauman, situated in the country of Blankenburg, which belongs to the Duke of Brunswick, to the south of the city of that name, to the east of Elbingerode, and to the north of the village of Rubeland, the nearest inhabited place, in a hill which forms one of the last declivities of the Hartz toward the east. It has been described by many authors, among whom we shall particularly mention the great Leibnitz, in his ProtogÆa, pl. i. p. 97, where he gives a map of it, borrowed from the Acta Eruditorum 1702, p. 305.

Its general direction is east and west, but the entrance faces the north. It is very narrow, although it is under a pretty large natural vault. The first cave is the largest. From this to the second, one must descend by another narrow passage, at first by creeping, and afterwards by a ladder. The difference of level is 30 feet. The second cave is the richest in stalactite of all forms. The passage to the third cave is at first the most difficult of all, and we have to climb with hands and feet; but it afterwards enlarges, and the stalactites of its walls are those in which the imagination of the curious has pretended to see the best characterized figures. It has two lateral dilatations, of which the map of the Acta Eruditorum makes the third and fourth caves. At its extremity, we have still to ascend, in order to arrive at the real third cave, which forms a sort of portal. Behrens says, in his Hercynia curiosa, that it cannot be reached, because it would be necessary to descend more than 60 feet; but the above mentioned map, and the description of Von der Hardt, which accompanies it, describe this third cave under the name of the Fifth, and place beyond it a narrow passage, terminated by two small grottoes. Lastly, Silberschlag, in his Geogony, adds, that one of these grottoes leads to a narrow passage, which, descending much, leads under the other caves, and terminates in a place filled with water. There are still many bones in these remote and little frequented parts. Most of those bones which are in collections from this cave, or which have been described, are of the bear genus.

A second cave, nearly as celebrated as the former, and very near, is that which is named, after the unicorn, EnihornshÆle, at the foot of the chateau of Scharzfels, in a part of the Electorate of Hanover which is named the Dutchy of Grubenhagen, and nearly upon the last southern declivity of the Hartz. It has also been described by Leibnitz, as well as by M. Deluc, in his Letters to the Queen of England. The entrance is 10 feet high, and 7 broad. We descend vertically 15 feet into a sort of vestibule, the roof of which lowers to such a degree, that, at the end of 60 feet, we are obliged to creep. After a long passage, we come to two other caves, according to Leibnitz; but Behrens adds three or four, and says, that, according to the country people, we might penetrate nearly two leagues.

Bruckmann, who gives a map of this cavern (Epistol. Itin. p. 34.), represents only five caves, arranged nearly in a straight line, and connected by extremely narrow passages. The second is the richest in bones; the third, which is the most irregular, has two small lateral caves; the fifth is the smallest, and contains a fountain. Of the bones which have been taken from it, some are in the possession of M. Blumenbach and other naturalists; and others have been figured by Leibnitz and Mylius. They belong to the bear, hyena, and tiger or lion genera.

The chain of the Hartz also presents some other caves of less celebrity, although of the same nature mentioned by Behrens in his Hercynia curiosa, namely,

The cave of Hartzburg, under the castle of the same name, above Goslar to the south. We do not know why BÜsching disputes its existence. It is true that Behrens cites J. D. Horstius erroneously, for having seen bones of various animals taken from it; for Horstius speaks only (Obs. Anat. dec. p. 10.) of the cave of Scharzfels.

The cave of Ufftrungen, in the county of Stollberg, to the south of the castle of that name. It is named in the country Heim-knohle, or Hiding-hole. Behrens thinks that fossil bones might be found in it.

Another cave of the same neighbourhood, is named Diebsloch, Thieves’ Hole. Skulls have been found in it, which were supposed to be human.

We shall not speak here of those caves of the Hartz in which bones have not been discovered. And even those in which they have been found, are, at the present day, almost exhausted, it being only by breaking the stalactite that any can be obtained, so much of them had been taken away for selling as medicines.

The caves of Hungary come after those of the Hartz, with reference to the remoteness of the time at which they have been known. The first notice of them is due to Paterson Hayn, (Ephem. Nat. Cur. 1672, Obs. cxxxix. and cxciv.) Bruckmann, a physician of WolfenbÜttel, afterwards described them at length. (Epistola Itineraria, 77, and Breslauer Sammlung, 1725, First Trim. p. 628.) They are situated in the county of Liptow, on the southern declivities of the Carpathian mountains. They are known in the country by the name of Dragons’ Caves, because the people of the neighbourhood attribute to those animals the bones which occur in them, and with which they have been acquainted from time immemorial; but all those which have been figured by authors belong to the Bear family, and to the species which is named the Great Cave Bear (Grand Ours des cavernes).

The caves of Germany the richest in bones are those of Franconia, of which J. F. Esper, a clergyman of the country of Bayreuth, has given a very detailed description in a work, printed in French and German, entitled, Description des Zoolithes nouvellement decouvertes, &c. Nuremberg Knorr. 1774, folio, with 14 coloured plates, and in a memoir inserted among those of the Berlin Society of Naturalists, vol. ix. 1784, p. 56. Another description was afterwards given, under the title of Objets dignes de remarque des environs de Muggendorf, by J. C. RosenmÜller, folio, with coloured views, Berlin, 1804. And more lately, M. Goldfuss, at present Professor of Natural History at Bonn, and Secretary of the Academia NaturÆ Curiosorum, has made them the subject of a particular work printed in 1810 in German, under the title of Environs of Muggendorf, in which he describes them with the greatest care, as well as the surrounding country, of which he gives a very correct topographical chart. A great part of these caves is situated in a small bailiwick, named Streitberg, which was formerly a dependence upon the country of Bayreuth, but was inclosed in that of Bamberg, and now forms part of the kingdom of Bavaria. The greatest number occur in a small peninsula, formed by the river of Wiesent, which falls into the Pegnetz, and belongs to the basin of the Main.

However, the chief of all these astonishing caves, those of Gaylenreuth, are beyond the limits of this peninsula, being on the left bank of the Wiesent, to the north-west of the village from which it derives its name. The entrance is perforated in a vertical rock; it is 7½ feet high, and faces the east. The first cave turns to the right, and is upwards of 80 feet long. The unequal heights of the vault divide it into four parts; the first three are from 15 to 20 feet high, the fourth is only 4 or 5. At the bottom of this latter, on the level of the floor, there is a hole 2 feet high, which affords a passage to the second cave: it has first a direction to the south, over a length of 60 feet by 40 in breadth, and 18 in height; it then turns to the west for 70 feet, becoming lower and lower until at length the height is only 5 feet. The passage which leads to the third cave is very inconvenient, and one has to turn through various corridors: it is 30 feet across, and from 5 to 6 in height. The ground in it is kneaded with teeth and jaws. Near the entrance is a pit of from 15 to 20 feet, to which one descends by a ladder. After having descended, we come to a vault of 15 feet diameter by 30 in height; and towards the side at which the descent is made there is a cave strewed with bones. On still descending a little, a new arcade is met with, which leads to a cave 40 feet long, and a new pit of from 18 to 20 feet deep. After descending this, we reach a cavern about 40 feet high, all strewed with bones. A passage, of 5 feet by 7, leads to a grotto of 25 feet in length by 12 in breadth. Canals, 20 feet in length, conduct to another grotto of 20 feet in height. Lastly, there is another cave, 83 feet broad and 24 high, in which more bones are found than in any of the others.

The sixth cave, which is the last, has a northerly direction, so that the whole series of caves and passages nearly describes a semicircle.

A fissure in the third cave led to the discovery, in 1784, of a new cave, 15 feet long and 4 broad, in which the greatest quantities of hyena and lions’ bones were found. The aperture was much too small for these animals to have passed through it. A particular canal which ended in this small cave has afforded an incredible number of bones and large skulls entire.

In the Philosophical Transactions of 1822, pl. xxvi. there may be seen a profile of this cave, taken on the spot in 1816, by Professor Buckland, in which is to be especially remarked an enormous mass, entirely composed of bones enveloped in the stalactite, and thus forming an osseous breccia, but of quite a different nature from those which occur at Gibraltar and other places[432].

The cave of Gaylenreuth is one of those the bones of which are most completely known, by the researches which have been made or caused to be made in it for a long time back by distinguished naturalists, such as MM. Esper, de Humboldt, Ebel of Bremen, RosenmÜller, Soemmering, Goldfuss, &c., and by the numerous and rich collections which these researches have produced. According to the examination which Cuvier has made of the principal of these collections, three-fourths of the bones found there belong to the Bear genus, and to two or three species of that genus. The others belong to the hyena, tiger, wolf, fox, glutton, and polecat, or some nearly allied species. There are also found, although in much smaller number, bones of herbivorous quadrupeds, and, in particular, deer, of which fragments are in the possession of M. Ebel. It would even appear from a passage of M. Soemmering’s, that a parcel of bones had been got in it belonging to an elephant’s skull[433]. According to RosenmÜller, there were found in it bones of men, horses, oxen, sheep, deer, roes, mules, badgers, dogs, and foxes, but which from the researches made by him in the cave itself, and from their state of preservation, must have been deposited at periods much later than those of the bear, tigers and hyenas[434].

The small peninsula situate nearly opposite to this cave, presents several other caves, as the Schoenstein, or Beautiful Rock, which contains seven contiguous caverns. The Brunnenstein, or Fountain Rock, in which, according to Esper, there are only found bones of known species, such as badgers, dogs, foxes, hogs, and deer; but Esper had too little anatomical knowledge for his testimony to be entirely relied on with respect to this. These bones are sometimes encrusted with stalactite. It contains also the Holeberg, or Hollow Mountain, in which eight or ten caves form a series of 200 feet in length, with two entrances. Bones of the same bears as at Gaylenreuth, are found here in various lateral depressions; and there are also deer and hogs.—The Wizerloch, so named from an ancient Sclavonic deity formerly worshipped there, the most dismal cavern of the whole country, situate in its most elevated part, and in which some vertebrÆ have been found. It is more than 200 feet long. The Wunderhoehle, which takes its name from its discoverer, has been known since 1773: its extent is 160 feet.—Lastly, the Cave of Klaustein, consisting of four grottoes, and upwards of 200 feet deep. Bones have been found in the third grotto, and most abundantly towards its extremity. It might be supposed that the name Klaustein signified Claw-rock, and it would thus accord very well with a place where, without doubt, as at Gaylenreuth, a multitude of ungual phalanges of bears and animals of the tiger kind have been found. But M. Goldfuss asserts, that it was called Klaustein, or St Nicholas’s Rock, after a chapel of this name, which formerly stood upon it.—There are still the Geiss-knok, or Goat Cave, and a cave discovered in 1793. M. RosenmÜller found in them two human skeletons already covered with stalactite.

The country which surrounds this small peninsula has itself several caves, independently of that of Gaylenreuth, as those of Mockas, Rabenstein, and Kirch-ahorn, three villages, situate, the first to the south, and the other two to the north-east of Gaylenreuth. Bones were formerly found in the first. The last bears in the country the expressive name of Zahn-loch, or Tooth Cave; it also bears the name of Hohen-mirschfeld, a village on whose ground it is situate; and the country people have long been in the habit of seeking in it those bones, which they imagined to be medicinal. MM. RosenmÜller and Goldfuss have in fact found bear and tiger bones. There are two others in the territory of the same village, of which the one named Schneider-loch (Tailor’s Hole), is said to have furnished the vertebrÆ of an elephant. That of Zewig, close upon Waschenfeld, at the very edge of the Wiesent, is nearly 80 feet deep; and it is said that skeletons of men and wolves were found in it.

All these hills, containing caves in their interior, and situate so near each other, seem to form a small chain, interrupted only by brooks, and which joins the more elevated chain of the Fichtelberg, in which are the highest mountains of Franconia, and from which flow the Main, the Saale, the Eger, the Naab, and many small rivers. M. RosenmÜller, and after him, others assert, that those which are in the hills to the north of the Wiesent, contain not a single fragment of bone, while those to the south are filled with them.

In 1799, a cave, remarkable for its situation, was discovered, which connects in some measure those of the Hartz with those of Franconia. It is the Cave of GlÜcksbrun, in the bailiwick of Altenstein, in the territory of Meinungen, on the south-western declivity of the chain of the Thuringerwald (Blumenb. ArchÆol. Telluris, p. 15. Zach. Monate. Corresp. 1800, January, p. 30.) It is the same which M. RosenmÜller names Libenstein, on account of its being on the road from Altenstein to this latter, which is a bathing place. There is a description of it by M. Kocher, in the Magazin fÜr Mineralogie, by M. C. E. A. De Hof, 1st band. heft. iv. p. 427. The limestone in which it is situate rests upon bituminous schist, and, rising much upwards, comes to rest upon primitive rocks. The limestone varies in hardness and in the nature of its fracture, and contains marine petrifactions, such as pectinites, echinites, &c.

In making a road, there was discovered an opening, from which a very cold air issued, which determined the Duke of Saxe-Meinungen to have it farther examined. A narrow passage, of twenty feet in length, was found, which led to a cave of thirty-five feet, having a breadth of from three to twelve, and a height of from six to twelve, according to the places, and terminated by a large piece of rock, which was removed. The labour of two years discovered and cleared a series of caves connected together, and of which the bottom rose and fell alternately. They terminate in a place where water flows; but various lateral fissures make it probable that there are still several caves which have not been opened, and that they perhaps form a sort of labyrinth.

The bottom and walls of this cave are furnished with the same mud as the others, but blacker. The bones were pretty numerous, and tinged with the same colour, but only two tolerably entire skulls were obtained. That of which M. Kocher gives a figure, is the species of bear named Ursus spelÆus. There are also caves of this kind in Westphalia. J. Es Silberschlag, in the Mem. des Naturalistes of Berlin (Schriften, vol. vi. p. 132), describes the one called Kluter-hoehle, near the village of Oldenforde, in the county of Mark, on the edge of the Milspe and Ennepe, two streams which fall into the Ruhr, and with it into the Rhine. Its entrance is about half-way up a hill called Kluterberg, is only three feet three inches high, and faces the south. The cave itself forms a true labyrinth in the interior of the mountain.

Not far from this, in the same county, at Sundwich, two leagues from Iserlohn, is another cave, which, for about twenty-five years back, has furnished a very large quantity of bones, part of which has been carried to Berlin, and the rest has remained in the country in the hands of various individuals[435].

If we cast a glance upon a general map, it is not difficult to perceive a certain continuity in the mountains in which these singular caves occur. The Carpathians join with the mountains of Moravia and those of Bohemia called Boehmerwald, to separate the basin of the Danube, from those of the Vistula, Oder and Elbe. The Fichtelgebirge separates the basin of the Elbe from that of the Rhine. The Thuringerwald and the Hartz continue to limit the basin of the Elbe, by separating it from that of the Weser.

These different chains have but slight intervals between them. The caves of Westphalia alone are not connected in so evident a manner with the others.

Very lately, bones have been discovered in a cavern, which extends more towards the south, and is even situate on the other or Italian side of the Alps. It is that of Adelsberg in Carniola, a place situate on the great road from Laybach to Trieste, and about half way between these two cities. The whole of this country is full of caverns and grottoes, which have given rise to numerous sinkings of the surface, thus giving a very singular appearance to the country. Several of these caverns have long been celebrated among naturalists. That of Adelsberg is generally visited by travellers, on account of its being near the highway, and because a river called the Piuka or Poike is lost there, forming a subterranean lake, and emerging again on the north side, under the name of Unz. A hole which the Chevalier de Lowengreif discovered in 1816, in one of its walls, at the height of 14 fathoms, conducted him to a series of new caves of vast extent, and of incomparable beauty, from the lustre and variety of their stalactites.

A part of these caves was, however, known, and must be, or have been accessible, by some other place, for inscriptions were found in them with dates, from 1393 to 1676, together with human bones, and entire carcases, that had been buried there. A German pamphlet was published at Trieste, in which are described all the windings of these subterranean passages, their different halls, their domes, their columns, and all the other appearances produced by their stalactites. We shall not follow the author (M. de Volpi, Director of the School of Commerce and Navigation at Trieste) through this immense labyrinth. Let it suffice to say, that this zealous naturalist asserts his having proceeded more than three leagues, almost in a straight line, and that he was only stopped by a lake which rendered it impossible to go on. It was about two leagues from the entrance that he discovered bones of animals, of which he gives figures, and which he describes under the name of PalÆotheria. He had the politeness to communicate to me, says Cuvier, his drawings the year before, but it appears my reply did not reach him, for he makes no mention of it in his book.

Be this as it may, his figures clearly shewed that the bones in question belonged to the great cave-bear. In fact, several of these bones having been presented to the Congress of Laybach, Prince Metternich, whose enlightened taste for the advancement of knowledge has already been of so much service, had the goodness to address them to Cuvier, who disposed them in the Royal Cabinet, where any one may satisfy himself as to their species.

There are, without doubt, caves in many other chains, and several are known in France. Caves occur in Suabia, but no bones have been found in them; and, in general, it appears, that, before the last discoveries, and especially that which has been made in Yorkshire, none were known but those of Germany and Hungary that were rich in bones of carnivora. In truth, the rock of Fouvent, and which contains in one of its cavities bones of hyenas, and at the same time those of elephants, rhinoceroses and horses, might be considered as belonging to this order of phenomena; but as it was not explored to any depth, it cannot be certain that it is so.

The case is different with the Kirkdale Cavern. It having been visited immediately after its discovery by several well informed persons, and especially by Mr Buckland, every thing has been made known with respect to it. It is situated in the East Riding of the county of York, twenty-five miles NNE. of the city of York, and at about the same distance to the west from the sea and the town of Scarborough. The small river of Hodgebeck is lost under ground in the neighbourhood, much in the same way as the Piuka, near Adelsberg. It is placed in one of the limestone hills which form the northern boundary of the vale of Pickering, the waters of which fall into the Derwent. Mr Buckland compares the stone to that of the last strata of the Alpine limestone, such as are seen near Aigle and Meillene.

It was in the course of the year 1821, that some labourers working at a quarry, discovered by chance the opening, which was closed by rubbish, covered over with earth and turf. It is about 100 feet above the neighbouring brook. It can be entered to the distance of 150 or 200 feet, but we can only walk erect in some places, on account of the stalactites. On its sides there are seen spines of sea-urchins and other marine remains, incrusted in the mass of the rock; but it is on the bottom, and there only, that there is found the stratum of mud, of about a foot thick, stuck full of bones, as at Gaylenreuth. This mud, and the bones which it contains, are, in various places, covered or penetrated with stalactite, especially near places where the rock has lateral fissures.

The discovery having acquired much celebrity, a great number of people procured bones from it, and placed them in various public depots. Specimens have been deposited in the York Institution, that of Whitby and Bristol, the British Museum, the Museum of Oxford and Cambridge, and by Mr Young of Whitby, in the College Museum of Edinburgh; but the finest collection of the bones of Kirkdale was presented to Cuvier, and by him deposited in the Royal Cabinet in Paris. The greatest number of these bones without comparison, belong to hyenas of the same species as those of the caverns of Germany; but there are also many of other large and small animals, which Mr Buckland supposes to form twenty-one species. From the pieces which I have under my eye, says Cuvier, there indisputably occur bones of the elephant, hippopotamus, horse, an ox of the size of the common deer, rabbits, field-rats; also bones of some other carnivora, namely, of the tiger, wolf, fox, and weasel. All these bones and teeth are accumulated on the ground, broken and gnawed, and there are even seen marks of the teeth which have fractured them. There are even intermixed with them excrements which have been recognized as perfectly similar to those of the hyena[436].

The hills in which these caverns occur resemble each other in their composition: they are all of limestone, and all produce abundance of stalactites. These stalactites line the walls, narrow the passages, and assume a thousand various forms. The bones are nearly in the same state in all these caverns: detached, scattered, partly broken, but never rolled, and consequently not brought from a distance by water; a little lighter and less solid than recent bones, but still in their true animal nature, very little decomposed, containing much gelatine, and not at all petrified. A hardened, but still easily frangible or pulverisable earth, also containing animal parts, and sometimes blackish, forms their natural envelope. It is often impregnated and covered with a crust of stalactite. A covering of the same nature invests the bones in various places, penetrates their natural cavities, and sometimes attaches them to the walls of the cavern. This stalactite is often coloured reddish by the animal earth which is mixed with it. At other times its surface is stained black; but it is easy to see that these appearances are caused by modern occurrences, and have no immediate connection with the cause which brought the bones into these cavities. We even daily see the stalactite increasing and enveloping here and there groups of bones which it had formerly respected.

This mass of earth, penetrated by animal matter, indiscriminately envelopes the bones of all the species; and, if we except some found at the surface of the ground, and which had been transported there at much later periods, which may also be distinguished by their being much less decomposed, they must all have been interred in the same manner, and by the same causes. In this mass of earth there are found, confusedly mingled with the bones (at least in the cave of Gaylenreuth), pieces of a bluish marble, of which all the corners are rounded and blunted, and which appear to have been rolled. They singularly resemble those which form part of the osseous brecciÆ of Gibraltar and Dalmatia.

Lastly, what further conspires to render this phenomenon very striking, is, that the most remarkable of these bones are the same in these caverns, over an extent of more than two hundred leagues. Three-fourths and upwards belong to species of bears, which are now extinct. A half, or two-thirds of the remaining fourth, belong to a species of hyena, which is equally unknown at the present day. A smaller number belong to a species of the tiger or lion kind, and to another of the wolf or dog genus; lastly, the most diminutive have belonged to various small carnivora, as the fox, the polecat, or at least species very nearly allied to them, &c.

The Kirkdale Cavern, however, forms a notable exception, inasmuch as none, or very few, bones of bears are found in it, and in its being the hyena that appears to predominate among the carnivora.

The species so common in the alluvial formations, the elephants, rhinoceroses, horses, oxen or aurochs, and tapirs, are of very rare occurrence in the caves of Germany. There are even some in which no one is said to have found them, and the only bones of herbivora mentioned are remains of deer. In this point also, however, the Kirkdale cave differs much from the others, inasmuch as it abounds almost as much in bones of large and small herbivora, as in bones of carnivora. All the great pachydermata of the alluvial formations are seen in it: the elephants, rhinoceroses and hippopotami. There are also seen in it bones of oxen, deer, and even small bones of mice and birds. But there are no bones of marine animals of any species, either at Kirkdale or in Germany. Those who have pretended that they saw bones of seals, morses, or other similar species, have been led into error by the hypothesis which they had previously adopted.

These bones of carnivora, so numerous in the caves, are rare in the great alluvial strata; the hyena alone has been seen in any quantity at Canstadt, near Aichstedt, and in some other places. There have also been found some traces of bears in Tuscany and Austria, but their relative proportion is always infinitely less than in the caves; and it is always sufficiently proved by these circumstances, that these various animals have lived together in the same countries, and have belonged to the same epoch.

Cuvier concludes, there can only be imagined three general causes which might have placed these bones in such quantity in these vast subterranean cavities. Either they are the remains of animals which inhabited these abodes, and which died peaceably there; or inundations and other violent causes have carried them into these cavities; or, lastly, they had been enveloped in rocky strata, the dissolution of which produced these caverns, and they have not been dissolved by the agent which carried off the matter of the strata.

This last cause is refuted by the fact, that the strata in which the caves occur contain no bones; and the second by the entireness of the smallest prominences of the bones, which does not permit us to think that they had been rolled; for if some bones are worn, as Mr Buckland has remarked, they are only so on one side, which would only prove that some current has passed over them, and in the deposit in which they are. We are, therefore, obliged to have recourse to the first supposition, whatever difficulties it presents on its part, and to say that these caves served as a retreat to carnivorous animals, and that these carried there, for the purpose of devouring them, the animals which formed their prey, or the parts of these animals.

Mr Buckland has observed, that the hyena bones are not less broken and splintered than those of the herbivorous animals; from which he concludes, that the hyenas had devoured the dead bodies of their own species, as those of the present day still do.

These animals attack each other during their life; for the fossil head of a hyena is preserved, which had evidently been wounded and afterwards healed[437].

This supposition is moreover confirmed by the animal nature of the earth in which these bones are found[438].

This much is certain, that the establishment of these animals in the caves has taken place at a much later epoch than that at which the great rocky strata have been formed, not only those which compose the mountains in which the caves are situated, but the strata of much newer origin. No permanent inundation has penetrated into the subterranean dens, and formed a regular rocky deposit. The mud arising from the proper decomposition of these animals, and the stalactites that have been filtered through the wall of the caves, are the only matters which cover these remains, and these stalactites increase so rapidly, that M. Goldfuss already found a layer of them covering the names of MM. Esper and RosenmÜller, whose visits did not date thirty years before his own. The rolled stones that are met with, and the marks of detrition observed on some bones, announce, at the very utmost, but passing currents.

But how have so many ferocious animals which peopled our forests been extirpated? All the reply we can make is, that they must have been destroyed at the same time, and by the same cause, as the large herbivora, which, like them, also peopled these forests, and of which no traces remain at the present day any more than of them.

ACCOUNT OF THE CAVE CONTAINING BONES AT ADELSBERG IN CARNIOLA.

The following interesting account of the cave, slightly noticed at pages 524 and 525, is extracted from a memoir by M. Bertrand Geslin, Member of the Natural History Society of Paris, published in the number of the Annales des Sciences Naturelles for April 1826.

M. Cuvier, says Gesler, speaking of the Adelsberg Cave, from the account published by M. Volpi of Trieste, says, that it was nearly two leagues from the entrance where he discovered bones of animals.

Having visited this cave myself, I am obliged to say that M. Volpi’s assertion as to this matter is not very correct. On my way to Trieste, in July 1823, before going to Adelsberg, I had the advantage of seeing M. Volpi. In shewing me the bones collected by him at Adelsberg, he also assured me that they were found two leagues from the entrance of the cave, and only in a very compact block of several cubic feet, from which it was not possible to procure more, as he had taken all that he could easily remove.

Notwithstanding this discouraging account, I betook myself to Adelsberg, in order to see a sample of those immense caverns of secondary limestone. The entrance of the cave is situated in a white compact secondary limestone, lying in great beds inclined to the south-west, at an angle of from 30 to 35 degrees. At fifty paces from the entrance, we find ourselves as in a large apartment, which crosses the torrent of the Pinka. After passing to the left bank of this torrent, we enter a rather low and not long passage, which leads to a second apartment of an elongated form. It is here that the line of chambers truly commences. They are of large but variable dimensions, and are situated nearly upon a horizontal plane.

On entering this second chamber, I saw that the ground was formed of a yellow and reddish clayey mud, from one to two feet thick, and more or less impregnated and covered with crusts of yellow stalagmites. In the places where it offered little resistance, I dug it up with the point of my hammer, and was fortunate enough to disunite some fragments of bone, although, from what had been said to me, I ought not to have expected to find them. From this I was convinced, that if M. Volpi had only found bones at a distance of two leagues from the entrance, it was because he had not been at the trouble to search for them nearer. I fell to work with more ardour, and succeeded in digging up some in good preservation, such as radii, cubiti, femora, humeri, fragments of jaws, calcarea, toes, vertebrÆ, &c., belonging to bears of different sizes, of the species termed Ursus spelÆus. It would appear that the hyena tribe is rather rare here, for I only procured a single bone belonging to it. It was particularly in two small lateral chambers, near the narrow passage, that I obtained a great quantity of these bones, the clay there having been dug up by the guides, in order to make the floor of the great apartment even with it.

I continued to dig as I advanced, and everywhere found bones more or less broken and enveloped in the clayey mud. After proceeding for half an hour, I fell in with a mass, in an apartment of considerable dimensions, which was of a conical form, and composed of blocks of compact white limestone, of all sizes, mixed with yellowish clayey mud. These blocks had their edges as sharp as if they had only been lately broken. The mass, which reached to the right wall of the cave, might be fifteen feet in height, and twenty in diameter at its base: it was covered with stalactite in several places. It was in this mass, at about ten feet above the floor of the cave, in the clayey mud that filled up the interstices between the blocks, that I found the entire skeleton of a young bear, in a space of two square feet at most. The bones which I dug out were the frontal part of the head, the lower jaw of the left side, the seventh cervical and eighth dorsal vertebrÆ; the eighth and fourteenth ribs of the right side; two tibia, femora, and cubiti, and two large canine teeth of another bear. If I could have raised up the limestone blocks, between which these bones lay, I might without doubt have procured a great part of this skeleton. There are still found here and there in the cave some small heaps of clayey mud, with fragments of white secondary limestone, as well as large isolated limestone blocks, which the guides are daily destroying, to make the floor even for the convenience of visitors.

I had only advanced an hour and a quarter’s progress into the cave, always finding bones, when the oil of my lamps beginning to fail, I was obliged to return without reaching the block in which M. Volpi had found the first bones. This block is without doubt owing to the same causes as the heap of which I have spoken above.

The manner in which these heaps exist, being composed of blocks of compact white secondary limestone, similar to that which forms the walls of the cave, with sharp edges, and piled upon each other, made me imagine that they might have fallen from the roof. As I returned, I examined the ceiling of the vaults with attention. As it was all covered over with stalactites, I could not discover any fissure.

From this short excursion in the Adelsberg cave, I am induced to believe, that the bones exist along the whole extent of the cave, and that they occur in two different ways; 1st, scattered in the clayey mud which forms the floor of the chambers; and, 2dly, buried in heaps formed of blocks of white secondary compact limestone, and yellow clayey mud.

The hypothesis which M. Cuvier admits as the most probable for explaining the presence of these bones in the caves, is that which would make these caves to have served as a retreat to carnivorous animals.

The presence of bones in the clayey mud of the floor of the Adelsberg cave accords well with this hypothesis; but the case is different with those which I found in the heaps of limestone blocks and clayey mud. The bones are not at the surface of the heap, but rather towards its middle part, buried among the blocks, and crushed by them. From this position, and the height at which the skeleton mentioned above occurs from the floor of the cave, it cannot be supposed that it formed part of the bones with which the bottom of the cave is strewed, nor that the blocks had fallen upon it. The bones contained in the heap in question must have been brought into their present position at the same time, and by the same cause as the limestone blocks. They could not, therefore, have belonged to animals which inhabited these caves, and died there peaceably.

If it be remarked, that these blocks, which are sometimes very large, heaped up above one another, and mixed with clayey mud, have their angles perfectly fresh, and are of the same nature as the limestone of the walls of the cave, it cannot be admitted that they have been brought from a distance. This mode of arrangement could only have been produced by their falling from the roof of the cave.

The following facts also give support to this opinion. In the cave of Gaylenreuth, a fissure of the third grotto, was the means, in 1784, of disclosing a new one, fifteen feet long and four broad, where the greatest quantity of hyena or lion bones were found. The aperture was much too small for these animals to have passed through it.

In a cave discovered in 1824, in the district of Lanark in Upper Canada, Mr Bigsby observed, that the floor was covered with debris of brown granular limestone, similar to that of the walls, and that the bones especially formed a heap there. He thinks that the animal, whose bones have been found in this cave, was much too large to have got into it alive or entire.—Silliman’s Journal, June 1825, p. 354.

It must therefore be also admitted here, either that the bones could only have got into the cave in the same manner as the heaps of blocks found in the Adelsberg cave; that is to say, by falling from the roof, or that the apertures have been closed since the period at which the animals were buried.

If it be now considered, 1st, That the surface of the secondary limestone mountains of Carniola is covered with a layer of reddish clay; and, 2dly, That the clayey mud of the heap in the Adelsberg cave is mineralogically the same as that which forms the floor of the cave; may it not be supposed, that the same catastrophe which produced the heaps in the cave may have, at the same time, introduced into it the reddish clayey mud of the surface, which, by extending itself over the floor of the cave, would have contributed to cover the bones that were lying there?

Moreover, may it not have been the case, that, after the caves had been inhabited by the carnivorous animals, the substances falling from above, and coming from the surface of the soil, may have carried along with the clayey mud and the bones of bears, the spoils of large herbivorous animals, which they may have met with, and which cannot be supposed to have sought refuge in these caves during life.

There will, no doubt, be objected to me, that opinion which maintains, that the bones of herbivora have been dragged into the caves by the carnivorous animals. This might certainly have been the case with regard to small species, but it is not probable that the bones of large species could have been introduced in the same manner.

Admitting as certain, at least with regard to the Adelsberg cave, that the limestone blocks and the bear bones which accompany them, have fallen from the ceiling, the phenomenon of caves containing bones would connect itself pretty well with that of osseous brecciÆ in a geological point of view. As M. Cuvier observes, “The nature of the rocks which contains the one and the other is not very different; and, besides, the fissures of caves being generally pretty wide, the bones would not have stuck, but would have fallen to the bottom, while those of the osseous brecciÆ being much narrower, and not so deep, would have retained the bones at no great distance from the surface of the soil.”

Thus, from the facts observed in the caves of Germany and England, and from that of the Adelsberg cave, which I have described above, we may conclude, 1st, That the presence of bones in caves has been produced at two different periods, which, without doubt, have not been very distant from each other; the first, that when the animals inhabited these caves; the other, that when they had been transported there by a somewhat general catastrophe; 2dly, That the second epoch was contemporaneous with the osseous brecciÆ, and was produced, like them, by a phenomenon or process of filling up.


TABULAR VIEW

OF

The Genera of Fossil Mammifera, Cetacea, Aves, Reptilia, and Insecta, exhibiting their Geognostical Number and Distribution.

Genera which are found Number of Species.
Names of Genera. Living only. Living, and in the Fossil State. Fossil only. In the Strata anterior to the Chalk. In the Strata of the Chalk. In the Strata posterior to the Chalk. In the Living State. In the Fossil State.
Mammifera.
Ursus, * * 4
Mustela, * * 2
Canis, * * 4
HyÆna, * * 1
Felis, * * 2
Phoca, * * 2
Didelphis, * * 2
Castor, * * 1
Arvicola, * * 2
Lagomys, * * 2
Lepus, * * 2
Megalonyx, * * 1
Megatherium, * * * 1
Elephas, * *
Mastodon, * * 6
Hippopotamus, * * 4
Sus, * * 1
Anoplotherium, * * 2
Xiphodon, * * 1
Dichobunus, * * 3
Anthracotherium, * * 2
Adapis, * * 1
ChÆropotamus, * * 1
Rhinoceros, * * 4
PalÆotherium, * * 8
Lophiodon, * * 5

Genera which are found Number of Species.
Names of Genera. Living only. Living, and in the Fossil State. Fossil only. In the Strata anterior to the Chalk. In the Strata of the Chalk. In the Strata posterior to the Chalk. In the Living State. In the Fossil State.
Tapirus, * * 1
Elasmotherium, * * 1
Equus, * * 1
Mus, * * 1
Cervus, * * 5
Bos, * * 4
Myoxus, * * 2
Cetacea.
Manatus, * * 1
Delphinus, * * 4
BalÆna, * * 3
Aves.(a)
Sturnus, * * 1
Pelecanus, * * 1
Charadrius, * 1
Reptilia.
Testudo, * * 6
Crocodilus, * * 6
Plesiosaurus, * 1
Ichthyosaurus, * * 4
Pterodactylus, * * * 3
Rana, * * 1
Mosasaurus, * * 1
Salamandra, * * 1

Genera which are found Number of Species.
Names of Genera. Living only. Living, and in the Fossil State. Fossil only. In the Strata anterior to the Chalk. In the Strata of the Chalk. In the Strata posterior to the Chalk. In the Living State. In the Fossil State.
Insecta.
Silpha,(b) * *
Curculio,(c) * *
Scorpio,(c) * *
Musca,(c) * *
Blatta,(c) * *
Tipula,(c) * *
Aranea,(c) * *
Ichneumon,(c) * *
Libellula,(d) * *
ScarabÆus,(d) * *
Scolopendra,(d) * *
Papilio,(d) * *
Hemerobia,(d) * *
Carabus,(d) * *

(a) It is extremely difficult to make out the genera of the Birds, whose remains occur in a fossil state, and there are more of them than those mentioned.

(b) In the lignite; the number of species cannot be given in the insects.

(c) In amber.

(d) In the fossil rocks, according to the old authors.


TABULAR VIEW

OF

The Classes, Orders, or Families, of Animals, occurring in a Living and Fossil State, with their Geognostical Distribution.

Number of Genera which are found Number of Species.
Names of
Classes,Orders,
or Families.
In the living state only. Living, and Fossil. In the Fossil state only. In the Strata anterior to the Chalk. In the Strata of the Chalk. In the Strata posterior to the Chalk. Total number of Genera. In the living State. In the fossil State.
Polyparia, 23 30 52 47 19 36 105 527 414
StellaridÆ, 4 2 4 4 76 4
EchinidÆ, 2 6 3 7 8 5 11 95 112
Annulosa, 2 1 1 1 2 3 17 29
Serpulacea, 2 3 1 3 3 3 6 36 69
Cirripeda, 8 2 1 2 10 50 17
TubicolÆ, 1 3 2 5 6 11 16
Pholadaria, 2 2 2 12 4
Bivalve shells, 18 61 24 44 25 51 103 1009 1104
Univalve shells, 33 87 28 27 16 93 148 1945 1544
Genera little known, 4 3 1 4 5
Crustacea, 21 5 5 2 9 28 54
Pisces, 54 6 11 2 55 60 183
Mammifera & Cetacea, 24 12 36 36 89
Aves,(a) 3 3 3 3
Reptilia, 4 4 3 2 4 8 23
Insecta, 14 14 14
Vegetabilia, 14 10 12 1 15 24

(a) The fossil remains of birds being very difficult to be recognized, the number of genera in that state is undoubtably much more considerable.

THE END.

                                                                                                                                                                                                                                                                                                           

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