TIME.—GEOLOGICAL PHENOMENA.

Time, an element in Nature’s Operations—Geological Science—Its Facts and Inferences—Nebular Hypothesis applied—Primary Formations—Plutonic and Metamorphic Rocks—Transition Series—PalÆozoic Rocks—Commencement of Organic Arrangements—Existence of Phosphoric Acid in Plutonic Rocks—Fossil Remains—Coal Formation—Sandstones—Tertiary Formations—Eocene, Miocene, and Pliocene Formations—Progressive changes now apparent—General Conclusions—Physics applied in explanation.

The influence of time, as an element, in producing certain structural arrangements, by modifying the operations of physical force, under whatever form it may be exerted, has scarcely been sufficiently attended to in the examination of cosmical phenomena. Every particle of matter is, as it were, suspended between the agencies to which we have been directing our attention. Under the influences of the physical powers, sometimes exerted in common, but often with a great preponderance in favour of one of them, every accumulated heap of mud or sand is slowly cohering, and assuming the form of a rock possessing certain distinguishing features, as it regards lamination, cleavage, &c.

The minute particles of matter are necessarily but slightly influenced by the physical forces: their action in accordance with the laws which determine physical condition is manifested in an exceedingly modified degree. But in all the operations of nature, what is deficient in power is made up in time, and effects are produced during myriads of ages, by powers far too weak to give satisfactory results by any experiments which might be extended even over a century.

If, with the eye of a geologist, we take but a cursory glance over the Earth, we shall discover that countless ages must have passed during the progress of this planet to its present state. This is a fact written by the finger of nature, in unmistakeable characters, upon the mighty tablets of her mountains.

The superficial crust of the earth,—by which is meant only that film, compared with its diameter, which is represented by a few miles in depth—is composed of distinct mineral masses, exhibiting peculiar physical conditions and a certain order of arrangement. These rocks appear to have resulted from two dissimilar causes; in one class the action of heat is evident, and in the other we have either the slow deposition of matter suspended in water, or crystallization from solution; an aqueous origin is indicated by peculiarities of formation in all the more recent rocks.

There are few branches of science which admit of speculation to the extent to which we find it carried in geology. The consequences of this are shown in the popular character of the science. A few observations are made over a limited area, and certain structural conditions are ascertained, and at once the mind, “fancy free,” penetrates the profound depths of the earth, and imagination, having “ample room and verge enough,” creates causes by which every effect is to be interpreted. Such students, generally ignorant of the first principles of physics, knowing little of mineralogy, and less of chemistry, to say nothing of palÆontology, having none of the requisites for an observer, boldly assume premises which are untenable, and think they have explained a phenomenon,—given to the world a truth,—when they have merely promulgated an unsubstantiated speculation, which may have occasional marks of ingenuity, and but little else.

The carefully-made observations of those who, with unwearying industry, have traversed hill and valley, marked and measured the various characters, thicknesses, inclinations, and positions of rocks; who have watched the influences of heat in changing, of water in wearing, and the results of precipitation in forming, strata; who have traced the mechanical effects of earthquake strugglings and of volcanic eruptions, and, reasoning from an immense mass of accumulated facts, deduced certain general conclusions,—are, however, of a totally different character; and it is such observers as these who induced Herschel to say truly, that “geology, in the magnitude and sublimity of the objects of which it treats, undoubtedly ranks, in the scale of the sciences, next to astronomy.”[231]

The origin of this planet is involved in great obscurity, which the powers of the most gifted are unable to penetrate. It stands the work of an Almighty and Eternal mind, the beginning of which we cannot comprehend, nor can we define the period of its termination.

It may, probably, be safe to speculate that there was a time when this globe consisted of only one homogeneous stratum. Whether this remains,—whether, in our plutonic rocks, our granites, or our porphyries, we have any indications of the primitive state of the world, or whether numerous changes took place before even our unstratified formations had birth, are questions we cannot answer. The geologist looks back into the vista of time, and reckons, by phenomena, the progress of the world’s mutations. The stratified formations must have occupied thousands of ages; but before these were, during a period extending over countless thousands, the unstratified rocks may have been variously metamorphosed. It matters not whether we admit the nebular hypothesis or not,—a time must have been when all these bodies which now form the mass of this globe existed in the most simple state. We have already shown that very remarkable changes in external character and in chemical relations are induced, in the same simple element, by its having been exposed to some peculiar and different conditions; and already have we speculated on the probability that the advance of science will enable us to reduce the numerous elements we now reckon, to two or three. It is, therefore, by no means an irrational thought (which must, however, be held in the light of a pure conjecture), to suppose that at the beginning a mighty mass of matter, in the most attenuated state, was produced in space, and was gradually, under the influence of gravitation, of cohesive force, and of chemical aggregation, moulded into the form of a sphere. Ascending to the utmost refinement of physics, we may suppose that this mass was of one uniform character, and that it became in dissimilar parts—its surfaces and towards its centre—differently constituted, under the influences of the same powers which we now find producing, out of the same body, charcoal and the diamond, and creating the multitudinous forms of organized creations. These conditions being established, and carried to an extent of which, as yet, science has afforded us no evidence, chemical intermixture may have taken place, and a new series of compounds have been formed, which, by again combining, gave rise to another and more complex class of bodies.

The foundation of the superficial crust of the earth appears to be formed of a class of rocks which have resulted from the slow cooling of an immense mass of heated matter. These rocks have been called igneous; but are now more generally termed Plutonic (such as granites, syenites, &c.) Immediately above these, we find rocks which have resulted by deposition from water. These masses, having been exposed to the action of the heat below, have been considerably changed in their character, and hence they are often called metamorphic; but metamorphic rocks may, however, be of any age. The rocks formerly termed the transition series—from their forming the connecting link between the earlier formations—are now, from the circumstance of their being fossiliferous, classed under the general term of palÆozoic rocks, to distinguish them from the rocks in which no organic remains have been found. Above these are found the secondary strata, and, still more recently produced, we have a class now usually denominated the tertiary formations. “Eternal as the hills” is a poetic expression, implying a long duration; but these must, from the nature of things, eventually pass away. The period of time necessary for the disintegration of a granite hill is vastly beyond the powers of computation, according to our conception of the ordinary bounds of finite things. But a consideration of the results of a few years,—under the influence of the atmosphere and the rains,—as shown in quantity of solid matter carried off by the rivers, and deposited at their mouths, will tend to carry conviction to every mind, that a degrading process is for ever in action on the surface of the earth. The earth itself may be eternal, but the surface is continually undergoing mutation, from various causes, many of which we must briefly consider.[232]

In regarding geological phenomena, the absence of any fossil remains has often been supposed to indicate a period previous to any organic formations. The inorganic constituents of matter are probably of prior origin to the organic combinations; the vessel was constructed, upon which the organic creation was to float in space before any vital organisms were created. The supposed evidences in favour of the assumption that there was no organic life during the formation of the oldest rocks we know, are in some respects doubtful; and we can well understand that changes may have been induced in the earlier rock formations, by heat or by other powers, quite sufficient to destroy all traces of organized forms. It was long thought that phosphoric acid was not to be detected in rocks which are regarded as of igneous origin; and since this acid is peculiarly a constituent of organic bodies, this has been adduced as a proof that the plutonic rocks must have existed previously to the appearance of vegetable or animal life upon the surface of the globe. The researches of modern chemists have, however, shown that phosphoric acid is to be found in formations of granitic origin, in porphyry, basalt, and hornblende rocks.[233] If, therefore, we are to regard this substance as of organic origin, the rational inference is against the speculation; but there is no more necessity for supposing phosphorus to be formed in the animal economy than in the mineral kingdom, from which it will probably be found the animal obtained it.

Without attempting to enter into any account of the apparent progress of life over the earth, it appears desirable that some description should be given of the kinds of plants and animals which we know to have existed at different epochs. We shall thus learn, at least, some of the prevailing characteristics of the earth during its transitions, and be in a better condition for applying our knowledge of physical power to the explanation of the various geological phenomena.

Among the earliest races we have those remarkable forms, the trilobites, inhabiting the ancient ocean.

These crustacea bear some resemblance, although a very remote one, to the common wood-louse, and, like that animal, they had the power of rolling themselves into a ball when attacked by an enemy. The eye of the trilobite is a most remarkable organ; and in that of one species, Phacops caudatus, not less than two hundred and fifty lenses have been discovered. This remarkable optical instrument indicates that these creatures lived under similar conditions to those which surround the crustacea of the present day.

At the period of the trilobites of the Silurian rocks, all the animals contemporaneous with them had the organs necessary for the preservation of life in the waters.

Next in order of time to the trilobite, the most singular animals inhabiting those ancient seas, whose remains have been preserved, are the Cephalopoda, possessing some traces of organs which belong to vertebrated animals. There are numerous arms for locomotion and prehension, arranged in a centre round the head, which is furnished with a pair of sharp, horny mandibles, embedded in powerful muscles. These prehensile arms are provided with a double row of suckers, by which the animal seized its prey. Of these cephalopodous animals there are many varieties, but all of them appear to be furnished with powers of rapid locomotion, and those with shells had an hydraulic arrangement for sinking themselves to any depth of the seas in which, without doubt, they reigned the tyrants.

Passing by without notice the numerous fishes, which appear to have exhibited a similar order of progression to the other animals, we must proceed to the more remarkable period when the dry land first began to appear.

All the animals found in the strata we have mentioned are such as would inhabit the seas; but we gradually arrive at distinct evidence of the separation of the land from the water, and the “green tree yielding seed” presents itself to our attention; not that the strata earlier than this are entirely destitute of any remains indicating vegetable growth, but those they exhibit are such as, in all probability, may be referred to marine plants.

Those plants, however, which are found in the carboniferous series are most of them distinguished by all the characteristics of those which grow upon the land; we, therefore, in the mutilated remains of vegetation left us in our coal-formations, read the history of our early world.

Then the reed-like calamite bowed its hollow and fragile stems over the edges of the lakes the tree-ferns grew luxuriantly in the shelter of the hills, and gave a wild beauty to the humid valleys; the lepidodendrons spread themselves in mighty forests along the plains, which they covered with their curious cones; whilst the sigillariÆ extended their multitudinous branches, wreathing like serpents amongst the luxurious vegetation, and embraced, with their roots (stigmariÆ), a most extensive space on every side.[234]

The seas and lakes of this period abounded with minute animals nearly allied to the coral animals, which are now so actively engaged in the formation of islands in the tropical and southern seas. During the ages which passed by without any remarkable disturbance of the surface of the earth, the many bands of mountain limestone were formed by the ceaseless activity of these minute architects. Encrinites (creatures in some respects resembling star-fish) existed in vast numbers in the oceans of this time; and the great variety of bivalve shells, and those of a spiral character, discovered in the rocks of this period, show the waters of the newer palÆozoic period to have been instinct with life.

In the world then, as it does now, water acting on the dry land produced remarkable changes. We have evidence of extensive districts over which the most luxuriant vegetation must have spread for ages,—from the remains of plants in every state of decay,—which we find went to form our great coal-fields. These, by some changes in the relative levels of land and water, became covered with this fluid; and over this mass of decaying organic matter, sand and mud were for ages being deposited. At length, rising above the surface, it becomes covered with vegetation, which is, after a period, submerged; the same deposition of sand and mud again takes place, it is once more fitted for vegetable growth, and thus, cycle after cycle, we see the dry land and the water changing places with each other. This will be evident to every one who will carefully contemplate a section of one of the coal-fields of Great Britain. We find a stratum of coal lying upon a bed of under clay, and above it an extensive stratum of shale or sandstone, probably formed by the denudation of the neighbouring hills; and in this manner we have many strata of coal, shale, clay, ironstone, and sandstone alternating with each other; the coal-formations of the South Wales coal-field having the extraordinary thickness of 1500 feet. The lowest bed of this extensive series must at one time have been exposed as the surface of the country.

Ascending in the series, we have now formations of a more recent character, in which fishes of a higher order of organization, creeping and flying saurians, crocodiles and lizards, tortoises, serpents, and frogs, are found. The lias formations (a term corrupted from layers), consisting of strata in which an argillaceous character prevails, stand next in series. In these we have animals preserved in a fossil state, of a distinguishingly different character from those of the inferior strata. We meet with extended beds of pentacrinites, some inches in thickness; and their remains are often so very complete that every part of the skeleton can be made out, although so complicated that it cannot consist of less than 150,000 parts. In these formations we often find the curiously beautiful remains of the ammonites, of which a great variety have been discovered. Of the belemnites—animals furnished with the shell and the ink-bag of the cuttle-fish, with which it darkened the water to hide itself from enemies, numerous varieties have also been disentombed, with the ink-bag so well preserved, that the story of the remarkable fossil has been written with its own ink. In addition to these we find nautili; and sixty species of extinct fishes have been described by Agassiz from the lias of Lyme Regis alone.

When these rocks were in the progress of formation, there existed the ichthyosaurus, or fish-lizard, which appears, in many respects, to have resembled the crocodile of the Nile. It was a predatory creature of enormous power, and must have been the tyrant and terror of the seas which it inhabited. Its alligator-like jaws, its powerful eye, its fish-like fins, and turtle-like paddles, were all formed to facilitate its progress as a destructive minister. The plesiosaurus was, if possible, a still more extraordinary creation. To the head of a lizard was united an enormously long neck, a small and fish-like body, and the tail of a crocodile: it appears formed for existence in shallow waters, so that, when moving at the bottom, it could lift its head above the surface for air, or in search of its food. The flora of this period must have been extensive; and it resembled the vegetation which exists at present in Tropical regions.

We pass now to a new epoch, which is well distinguished by its animals from all that had preceded it. Races of reptiles still have place upon the earth, and we have now the megalosaurian remains; these animals possessing a strength and rapacity which would render them objects of terror as well as astonishment, could they be restored to the world which they once ravaged. An enormous bat-like creature also existed at this time—the pterodactyl—which, in the language of Cuvier, was, “undoubtedly, the most extraordinary of all the beings of whose former existence a knowledge is granted to us, and that which, if seen alive, would appear most unlike anything that exists in the present world.” “You see before you,” says the same writer, “an animal which, in all points of bony structure, from the teeth to the extremities of the nails, presents the well-known saurian characteristics, and of which no one can doubt that its integuments and soft parts, its scaly armour and its organs of circulation and reproduction, are likewise analogous. But it was, at the same time, an animal provided with the means of flying; and, when stationary, its wings were probably folded back like those of a bird, although, perhaps, by the claws attached to its fingers, it might suspend itself from the branches of trees.”[235]

From the disintegration of the older rocks have no doubt arisen those formations which are known as the oolitic series. In these strata are preserved the remains of plants and animals more resembling those which now exist upon the earth; and, for the first time,—unless the evidence of the footsteps of birds on the new red sandstone of America be accepted,—we meet with the remains of the feathered tribes.

In these formations we discover animals belonging to the class Mammalia,—the amphitherium and the phascolotherium,—which appear to have resembled, in many respects, the marsupial animals of New Holland.[236]

The wealden formations, which are the next in order of position, are a series of clays and sands, with subordinate beds of limestone, grit, and shale. These have, in some instances, been formed in the sea; but they are usually regarded as fresh-water deposits. All the older rocks bear evident marks of marine origin, unless some of the coal-measure strata may be regarded as otherwise; but nearly all the wealden series contain the remains of land, fresh-water, and estuary animals, and of land vegetables. The creatures which we discover, preserved, to tell the history of this period, are numerous, and have marked peculiarities to distinguish them from those already described, or from any now existing on the earth. We find land saurians of a large kind, and animals of all sizes; even insects, of which a great variety are found in the wealds. The remarkable iguanodon was an animal which, even by the cautious measurement of Professor Owen, must have been at least twenty-eight feet long; and this enormous creature was suspected, by Cuvier, and has been proved by Owen, to have been an “herbivorous saurian for terrestrial life.”[237] Dr. Mantell calculates that no less than seventy individuals of the iguanodon of all ages have come under his notice; and the bones of a vast number of others must have been broken up by the workmen in the few quarries of Tilgate grit; so that these creatures were by no means rare at the period of their existence.[238]

The uppermost of these secondary formations is the cretaceous or chalk group, which spreads over a large portion of south-eastern England, and is met with in all parts of Europe. This chalk, which is a carbonate of lime, appears to have been slowly precipitated from tranquil water, as, according to Sir Henry De la Beche, organic remains are beautifully preserved in it. Substances of no greater solidity than common sponges retain their forms, delicate shells remain unbroken, fish even are frequently not flattened, and altogether we have the appearances which justify us in concluding that, since these organic exuviÆ were entombed, they have been protected from pressure by the consolidation of the rock around them.[239]

Beneath the chalk exists what has been called, from its colour—derived from a silicate of the protoxide of iron,—green sand, and was, no doubt, formed by deposition from the same water in which the carbonate of lime was suspended,—the green sand falling to the bottom more readily from its greater specific gravity. “The tranquillity,” observes Sir Henry De la Beche, “which seems to have prevailed during this great accumulation of siliceo-calcareous matter, whether it may have been a deposit from water, in which it was mechanically suspended, partly the work of living creatures, or in a great measure chemical, is very remarkable.”[240]

In the chalk, the remains of the leaves of dicotyledonous plants and fragments of wood are found more abundantly than in the earlier strata, many of which are marked with the perforations of marine worms, indicating that they had floated for some time in the ocean. It should, however, be remembered, that these are not the first indications of vegetable life,—leaves have been found in the new red sandstone; and the flora of the coal formation must not be forgotten. The manner in which silica has deposited itself on organic bodies—such as the sponges—is curious; the whole of the organized tissue being often removed, and flint having taken its place. Flints formed by such a process as this abound in the upper chalk. The association of carbon and silicon, combined with oxygen, as we find them in the cretaceous formations, is most interesting, and naturally gives rise to some speculation on the relation of these two elements. Both carbon and silicon, as has been already shown, exist in several allotropic conditions; and, although the statements made by Dr. Brown relative to the conversion of carbon into silicon are proved to be grounded on experimental error, it is not improbable that a very intimate relation may exist between these elements.[241] The probability is, that the sponge animal has the power of secreting silica to give strength to its form. “Many species,” says Rymer Jones, speaking of recent sponges, “exhibiting the same porous structure, have none of the elasticity of the officinal sponge—a circumstance which is due to the difference observable in the composition of their skeletons or ramified frame-work. In such the living crust forms within its substance not only tenacious bands of animal matter, but great quantities of crystallized spicula, sometimes of a calcareous, at others of a siliceous, nature.” Thus, a frame of siliceous matter being formed by the living animal, a deposition of the same substance is continued after death.

Sea-urchins and star-fish, and numerous fossil shells, are found in these beds, which, however, differ materially from the remains of the same animals found in the earlier formations. A vast number of new species and genera of fish are also discovered in the chalk.

Nearly all the animals and plants which existed up to this period are now extinct, although they have some imperfect representatives at the present day.

The uppermost group, which has been called the supercretaceous or tertiary formation, appears in our island to have been formed during four great eras, as we find fresh-water deposits alternating with marine ones. The term eocene, which is the first or oldest deposit; miocene, which is the second; pliocene, which is the third; and the newer pliocene,—which is the fourth and last, have been applied to these formations, the names referring to the respective proportions of existing species found among their fossil shells.[242]

All these formations show distinct evidence of their having been deposited from still or slowly-flowing deep waters. Thus the eocene appears in the Paris basin,—formed clearly at an estuary, in which are mingled some interesting fresh-water deposits;—in the lacustrine formations in Auvergne; also at Aix; and in the north of Italy. It appears probable that, in the formations generally termed eocene, both fresh-water and marine deposits have been confounded, and several formations of widely-different eras regarded as the result of one. We have not yet been furnished with any distinct and clear evidence to show that the deposits of the Paris basin, and those of Auvergne, are of the same age. At all events, it is sufficient for our present purpose to know that they are the result of actions which are now as general as they were when the plastic clay of Paris, and its sulphate of lime, or the London clay, were slowly deposited.

As a general conclusion, we may decide that, at the eocene period, existing continents were the sites of vast lakes, rivers, and estuaries, and were inhabited by quadrupeds, which lived upon their thickly-wooded margins. Many remains, allied to those of the hippopotamus, have been found in the subsidences of this period.

Examples of the miocene or middle tertiary era are to be found in Western France, over the whole of the great valley of Switzerland, and the valley of the Danube. In these deposits we find the bones of the rhinoceros, elephant, hippopotamus, and the dinotherium, an extinct animal, possessing many very distinguishing features.[243]

The pliocene period has been termed the age of elephants, and is most remarkable for the great mastodons and gigantic elks, with other animals not very unlike those which are contemporaneous with man.

In the superficial layers of the earth, the diluvium, alluvium, peat and vegetable soil, we have a continuation of the history of the mutations of our globe and of its inhabitants, which has been here so briefly sketched. They bring us up to the period when man appeared in the world, since whose creation it is evident no very extensive change has been produced upon the surface. We have viewed the phenomena of each great epoch, marked as they are by new creations of organized beings, and it would appear as if, through the whole series, from the primary rocks up to the modern alluvial deposits, a progressive improvement of the earth’s surface had been effected, to fit it at last for the abode of the human race.

Thus have we preserved for us, in a natural manner, evidences which, if we read them aright, must convince us that the laws by which creation has ever been regulated are as constant and unvarying as the Eternal mind by which they are decreed. Our earth, we find, by the records preserved in the foundation-stones of her mountains, has existed through countless ages, and through them all exhibited the same active energies that prevail at the present moment. By precisely similar influences to those now in operation, have rocks been formed, which, under like agencies, have been covered with vegetation, and sported over by, to us, strange varieties of animal life. Every plant that has grown upon the earliest rocks which presented their faces to the life-giving sun, has had its influence on the subsequent changes of our planet. Each trilobite, each saurian, and every one of the mammalia which exist in the fossil state, have been small laboratories in which the great work of eternal change has been carried forward, and, under the compulsion of the strong laws of creation, they have been made ministers to the great end of forming a world which might be fitting for the presence of a creature endued with a spark taken from the celestial flame of intellectual life.

For a few moments we will return to a consideration of the operations at present exhibiting their phenomena, and examine what bearing they have upon our knowledge of geological formations.

During periods of immense, but unknown, duration, the ocean and the dry land are seen to have changed their places. Enormous deposits, formed at the bottom of the sea, are lifted by some mechanical, probably volcanic, force, above the waters, and the land, like the ocean surrounding it, teems with life. This state of things lasts for ages; but the time arrives when the ocean again floods the land, and a new state of things, over a particular district, has a beginning.

It must not be imagined that the changes which we have spoken of, as if they were the result of slow decay and gradual deposit, were effected without occasional violent convulsions. Many of the strata which were evidently deposited at the bottom of the sea, and, of course, as horizontal beds, are now found nearly vertical. We have evidence of strata of immense thickness having been subjected to forces that have twisted and contorted them in a most remarkable manner. Masses of solid rock, many thousand feet deep, are frequently bent and fractured throughout their whole extent. Mountains have been upheaved by internal force, and immense districts have suddenly sunk far below their usual level. By the expansive force due to that temperature which must be required to melt basaltic and trap rocks, the whole of the superficial crust of a country has been heaved to a great height, immense fissures have been formed by the breaking of the mass, and the melted matter has been forced through the opening, and overflowed extensive districts, or volcanoes have been formed, and wide areas have been buried under the ashes ejected from them. With the cause of these convulsions we are at present unacquainted.

We have evidence of the extent to which these forces may be exerted, in the catastrophes which have occurred within historical times, and which have happened even in our own day. Herculaneum and Pompeii, buried under the lava and ashes of Vesuvius, in an hour when the inhabitants of these cities were unprepared for such a fearful visitation,—the frightful earthquakes which have, from time to time, occurred in South America—are evidences of the existence of hidden forces which shake the firm-set earth. Similar ravaging catastrophes may have often occurred, and, involving cataclysms, swept the surface to produce the changes we detect over every part of the earth, compared with which the earthquakes and floods of history are but trivial things. Evidence has been adduced, to show that the mountains of the Old World may have approached in height the highest of the Andes or Himalayas, and these have not been destroyed by any sudden effect, but by the slow disintegrating action of the elements.[244] All these phenomena are now in progress: the winds and the rains wear the faces of the exposed rock; their dÉbris, mixed with decayed vegetable and animal matter, are washed off from the surface, and borne away by the rivers, to be deposited in the seas. Thus it is that the great delta of the Ganges is formed, and that a continual increase of matter is going on at the mouths of rivers. The Amazon, the Mississippi, and other great rivers, bear into the ocean, daily, thousands of tons of matter from the surface of the earth.[245] This is, of course, deposited at the bottom of the sea, and it must, in the process of time, alter the relative levels of the ocean and the land. Islands have been lifted by volcanic power from the bottom of the sea, and many districts in South America have been depressed by the same causes.

Changes as extensive have been, in all probability, effected by forces “equally or more powerful, but acting with less irregularity, and so distributed over time as to produce none of those interregnums of chaotic anarchy which we are apt to think (perhaps erroneously) great disfigurements of an order so beautiful and harmonious as that of nature.”[246] These forces are, without doubt, even now in action.

Had it not been for these convulsive disturbances of the surface, the earth would have presented an almost uniform plain, and it would have been ill-adapted for the abode of man. The hills raised by the disturbances of nature, and the valleys worn by the storms of ages, minister especially to his wants, and afford him the means of enjoyment which he could not possess had the surface been otherwise formed. The “iced mountain tops,” condensing the clouds which pass over them, send down healthful streams to the valleys, and supply the springs of the earth, thus securing the fertility and salubrity of the distant plains. The severities of climate are mitigated by these conditions, and both the people of the tropics and those dwelling near the poles are equally benefited by them.

Gravitation, cohesion, motion, chemical force, heat, and electricity, must, from that hypothetical time when the earth floated a cloud of nebulous vapour, in a state of gradual condensation up to the present moment, have been exercising their powers, and regulating the mutations of matter.

When the dry land was beneath the waters, and when darkness was upon the face of the deep, the same great operations as those which are now in progress in the depths of the Atlantic, or in the still waters of our inland lakes, were in full activity. At length the dry land appears; and—mystery of mysteries—it soon becomes teeming with life in all the forms of vegetable and animal beauty, under the aspect of the beams of a glorious sun.

Geology teaches us to regard our position upon the earth as one far in advance of all former creations. It bids us look back through the enormous vista of time, and see, shining still in the remotest distance, the light which exposes to our vision many of nature’s holy wonders. The elements which now make up this strangely beautiful fabric of muscle, nerves, and bone, have passed through many ordeals, ere yet it became fashioned to hold the human soul. No grain of matter has been added to the planet, since it was weighed in a balance, and poised with other worlds. No grain of matter can be removed from it. But in virtue of those forces which seem to originate in the sun, “the soul of the great earth,” a succession of new forms has been produced, as the old things have passed away.

Under the forces we have been considering, acting as so many contending armies, matter passes from one condition to another, and what is now a living and a breathing creature, or a delicate and sweetly-scented flower, has been a portion of the amorphous mass which once lay in the darkness of the deep ocean, and it will again, in the progress of time, pass into that condition where no evidences of organization can be found,—again, perhaps, to arise clothed with more exalted powers than even man enjoys.

When man places himself in contrast with the Intelligences beyond him, he feels his weakness; and the extent of power which he can discover at work, guided by a mysterious law, is such, that he is dwarfed by its immensity. But looking on the past, surveying the progress of matter through the inorganic forms up to the higher organizations, until at length man stands revealed as the chief figure in the foreground of the picture, the monarch of a world on which such elaborate care has been bestowed, and the absolute ruler of all things around him, he rises like a giant in the conscious strength of his far-searching mind. That so great, so noble a being, should suffer himself to be degraded by the sensualities of life to a level with the creeping things, upon which he has the power to tread, is a lamentable spectacle, over which angels must weep.

The curious connection between the superstitions of races, the traditionary tales of remote tribes, and the developments of the truths of science, are often of a very marked character, and they cannot but be regarded as instructive. In the wonders of “olden time” fiction has ever delighted; and a thousand pictures have been produced of a period when beings lived and breathed upon the earth which have no existence now.

Hydras, harpies, and sea-monsters, figure in the myths of antiquity. In the mythology of the northern races of Europe we have fiery flying dragons, and Poetry has placed these as the guardians of the “hoarded spirit” and protectors of the enchanted gold.

Through the whole of the romance period of European literature, nothing figures but serpents, “white and red,” toiling and fighting underground,—thus producing earthquakes, as in the story of Merlin and the building of Stonehenge. Flying monsters, griffins and others, which now live only in the meaningless embellishments of heraldry, appear to have been conceived by the earlier races of men as the representatives of power. Curious is it, too, to find the same class of ideas prevailing in the East. The monster dragons of the Chinese, blazoned on their standards and ornamenting their temples;—the Buddaical superstition that the world is supported on a vast elephant, which stands on the back of a tortoise, which again rests on a serpent, whose movements produce earthquakes and violent convulsions;—the rude decorations also of the temples of the Aztecs, which have been so recently restored to our knowledge by the adventurous travellers of Central America,—all give expression to the same mythological idea.

Do not these indicate a faint and shadowy knowledge of a previous state of organic existence? The process of communion between man of the present, and the creations of a former world, we know not; it is mysterious, and for ever lost to us. But even the most ignorant and uncultivated races of mankind have figured for themselves the images of creatures which, whilst they do really bear some resemblance to things which have for ever passed away, do not, in the remotest degree, partake of any of the peculiarities of existing creations.

The ichthyosaurus, and the plesiosaurus, and the pterodactylus, are preserved in the rude images of harpies, of dragons, and of griffins; and, although the idea of an elephant standing on the back of a tortoise was often laughed at as an absurdity, Captain Cautley and Dr. Falconer at length discovered in the hills of Asia the remains of a tortoise in a fossil state of such a size that an elephant could easily have performed the feat.[247]

Of the ammonites, we have more exact evidence; they were observed by our forefathers, and called by them snake-stones. According to the legends of Catholic saints they were considered as possessing a sacred character:—

And in addition to this petrifying process, one of decapitation is said to have been effected; hence the reason why these snake-stones have no heads.

We also find, in the northern districts of our island, that the name of “St. Cuthbert’s beads” is applied to the fossil remains of encrinites.

Thus we learn that, to a great extent, fiction is dependent upon truth for its creations; and we see that when we come to investigate any wide-spread popular superstition, although much distorted by the medium of error through which it has passed, it is frequently founded upon some fragmentary truth. There are floating in the minds of men certain ideas which are not the result of any associations drawn from things around; we reckon them amongst the mysteries of our being. May they not be the truths of a former world, of which we receive the dim outshadowing in the present, like the faint lights of a distant Pharos, seen through the mists of the wide ocean?

Man treads upon the wreck of antiquity. In times which are so long past, that the years between them cannot be numbered by the aids of our science, geology teaches us that forms of life existed perfectly fitted for the conditions of the period. These performed their offices in the great work; they passed away, and others succeeded to carry on the process of building a world for man. The past preaches to the present, and from its marvellous discourses we venture to infer something of the yet unveiled future. The forces which have worked still labour: the phenomena which they have produced will be repeated.