THE
COURSE OF CREATION:

BY
JOHN ANDERSON, D.D.

WITH A GLOSSARY OF SCIENTIFIC TERMS.

“In these morning-days of existence, Nature at once stamped, with her plastic hand, her lineaments of beauty and adaptation on everything she made. There is nothing omitted to be afterward supplied—nothing formed defective in a single part or organ that required to be corrected. The first discoveries in Geology at once speak conclusively of a plan or Course of Creation devised from the beginning—a power, not delegated, but linked forever with the first intelligent Cause—a world, through all its changes, continually presided over and ruled by Him who made it.”

CINCINNATI:
WM. H. MOORE & CO., PUBLISHERS,
118 MAIN STREET.
1851.

Entered, according to Act of Congress, in the year 1851, by
WM. H. MOORE & CO.,
In the Clerk’s Office of the District Court for the District of Ohio.

E. MORGAN & CO.,
STEREOTYPERS, PRINTERS AND BINDERS,
111 Main Street.

PREFACE.

It is no mitigation of an author’s temerity in publishing, that he can say for himself he had no intention, when collecting and arranging his materials, of ever submitting them to the eye of the public, or of provoking criticism by his speculations. Certain it is, however, I have often, and with severity at times, questioned myself as to the propriety of my geological pursuits, my ardent love of them, and their compatibility with the strict discharge of professional duty. My answer generally was, I sought not these things of themselves; they were hung up and displayed before me, wherever I went on pleasure, on business, or on duty. I simply inquired after their names; and of all the geological phenomena that have passed under my review, I can safely affirm of them, in their darkest, deepest places, they have uniformly led me “from nature up to nature’s God,” and have inscribed upon them in brightest characters—Benedictum sit nomen Dei.

How often, I have argued, in the leisure hours of life do we find men idling away their time, wasting it in vain talk, or consuming it in the most trifling pursuits, when a most interesting branch of science can be learned by wandering over the green fields, the rocky dell, the mountain side, or by the walk at even-tide, and there to hold converse with the Creator’s works and the records of his will? I have recalled the list of great and good men, whose names are imperishably connected with the science of geology, who have given much of their time to these researches, and who have reaped laurels from their discoveries. Can Buckland, Conybeare, Sedgwick, Sumner, Smith, Fleming, and Chalmers—all either explorers or expositors—and other eminent divines, have been engaged in improper pursuits, or have given the sanction of their authority to tenets and views connected with the scheme of nature that do not accord with the religious principle? Often on such occasions have I dwelt upon, and compared with my own humble pursuits, the lofty and impassioned descriptions of the Psalmist, where, sometimes in a single piece, he takes a magnificent sweep of the great master-keys of creation—the foundations of the steadfast earth—the course of the fluid waters—the revolutions of the sun and moon—the vicissitude of the seasons—the habits and instincts of the lower animals—the earthquake and volcano—and all recited as demonstrations of Divine wisdom and goodness, and all calculated to awaken and to sustain the devotional feelings of the heart.

Having, under the influence of such impressions, gathered, and now put together in this form, the notes of my researches, I do not mean to aver that I have visited every locality referred to, or personally observed everything noticed in the publication. Where so much has been done by others I have carefully examined their works. Where the field is so boundless, and the course of illustration necessarily so discursive, I have freely made use of their collected materials. Still, I have been chiefly induced to adopt the line of description from the Grampians to the Alps, because, at sundry though often distant periods, I have examined the various suites of rocks comprised betwixt these mountain boundaries. If there be any novelty in the volume, it will be found, not in the subject-matter itself nor in the mode of treating it, but by following the geographical sequence in the descriptions of the several geological formations, and their relations to each other in the countries passed over.

I have to express my acknowledgments to Messrs. W. and R. Chambers for a considerable number of the figures contained in the volume, and which have already appeared in one or other of their numerous publications. To Mr. David Page, than whom I do not know a better practical geologist, I am indebted for much valuable information, gleaned by him in an extensive acquaintance with most of the ground passed under review. The errors of the volume are my own, and these, I doubt not, in a science subject to such daily mutations and receiving daily such additions as the science of geology, will be found neither few nor venial.

Newburgh Manse, May, 1850.

CONTENTS

THE
COURSE OF CREATION.

GEOLOGY OF SCOTLAND.
PART I.

CHAPTER I.
INTRODUCTORY.

Geology is that branch of science which comprehends the knowledge of all that relates to the form, structure, mineral and fossil constituents, of the earth. The Scottish Grampians, it is generally admitted, form part of the lowest sections of its crust, to which the researches of geologists extend. We must go to other countries for any coeval, and, to North America for any older, competing land: and still, there, the rocks are of the same mineral qualities and arrangement. The Ben-Mac-Dhui group form the highest and most prominent masses in the whole range of these crystalline mountains.

When I first stood on the broad flat top of Ben-Mac-Dhui, I had no thought or purpose of ever recording its geological history. The excursion was undertaken simply for recreation, and a delightful one it proved. I longed to plunge into the deep recesses of the old forest, and to see the trees which nature had strewed with careless hand, ere, perhaps, Caledonia was tenanted by the human family. I looked down from its rugged sides, as I ascended, with awe and wonder—snatched a little alpine as I drew breath for the next spring—chipped a piece of granite as I obtained a footing over a yawning chasm, or breasted along by jagged precipitous defile,—and when, having fairly scaled the summit, I gazed out upon the world beneath, the feeling which for a moment flitted across my mind was one of no merely vain complacency, that I was then the most elevated subject of all the twenty-six or twenty-seven millions inhabiting the British Islands—and the lowest, too, in their stony regions! The mountains of the earth serve to inspire some of the loftiest sentiments that can fill the breast of its intelligent inhabitants. Imbosomed in their deep solitudes, man feels his own littleness, and is forced to inquire who made these wonders, and who sustains them? We are all the better, morally speaking, for leaving occasionally our daily-trodden haunts, where we see only human things, and hear only of the triumphs of human craft, the excitement of human passions, the littleness and vanity of even the noblest human daring. There is an image of Jehovah’s greatness impressed upon the outward face of nature, which for a time will awaken and sustain the most salutary reflections, breathing, as it were, a new life into the soul of the wayfarer. A man escapes from himself, forgetting the burden of a thousand petty cares, and rising above his sensual condition, when he looks upon the physical world in these its grander features and secluded scenes, which irresistibly speak to the inner sense of divinity, wisdom, and omnipotence.

The philosophy of the mountains, in the classic ages of Greece and Rome, inclined but little to any analysis of their grosser materials of earth and stone. The poetic and ideal were exclusively associated with their structures and form. The dii majores dwelt upon, and thundered from, their lofty summits. The clouds hovered in peaceful majesty over their council of sage or fierce debate. The elements were the ready ministers of their will; and Oreads, Dryads, and Naiads, peopling all the hills, forests, and streams, were the creations of that principle of the inner man, which has always searched for the spiritual behind and beyond the tangible attributes of Nature. Hence, too, the gnomes of the caverns, the spirits of the mists, the fairies of the glens, the kelpies of the torrents, were all the embodiment of forms, which fancy, in her later superstitions, has cast around the mountain landscape, with the witchery at once of the terrible and beautiful. The charm that spell-bound the human mind for ages, is not dissolved when, with ruder intent, we traverse these rocky solitudes, listening to the echo of our obedient hammer, learning the secrets of the universe amidst the voices of the everlasting hills, and seeing the wonders of the material world throwing light on the wonders of the spiritual.

We are reminded, among the mountains, of one of the first and loveliest of all material things, the creation of light. Loving them for their own sakes, as well as for the legends of the old world with which they are everywhere inscribed, the geologist takes to the hills with the first faint fresh streak of dawn. Emerging with earliest day from the somber shades of the forest which, like night, invests the prospects with its own sadness and gloom, speedily a scene of joy and activity bursts upon the sight. The light comes upon you like a real tangible thing. You see it glinting and breaking on the lofty ridge, then nearing down along the brown slope of the mountain, here projecting in long bright lines through the trees, and there—delicious, golden morn! first-born of Nature’s children, harbinger of life and gladness. How beautiful are thy first footsteps upon the heath-clad mountains! What a brood of gloomy thoughts thou dispellest, chasing them before thee, like yonder envious mists rising lazily from the plains, valleys, and streams, which they would fain hide from the eyes that now revel amid their exuberant loveliness. These lofty peaks are worthy altars for the beacon-fires of the orb of day, after he has finished his journey through the nations; and comes back to us, over the floating splendor of the sea, in the eastern heavens. And see! he hath lit a hundred on these splintered summits, which blaze now as they blazed centuries ago, and diminish not!

The view from this remarkable group of mountains—the most remarkable by far in the island—differs much from any other with which I am acquainted. The impressions at first are all very confused, and some time is required to resolve into distinct pictures the wondrous panorama before you. We have stood upon Skiddaw, where everything is clear, distinct, and palpable in distance and form; on Ben Lomond, where the far-stretch of perspective over lakes, rivers, and plains, is like a first lesson in painting; on Ben Lawers, where the eye sweeps rapidly over well known, familiar objects, spots of wood, glen, and mansion; on Ben Nevis, where you fancy yourself in mid-air, every object is so separate and apart, and so disposed the whole you are looking on, that the view is all downward upon the picture. But here, these dark giant masses crowd as it were against you. There is a struggle for the post of elevation. You are highest, no doubt of that; but so jealous all are these proud somber peaks, that every one seems to overlook, though yet actually beneath, the broad ample table-head of the center of the group. Sometimes one is tempted to leap across the narrow dells of separation, and at once master the geology of the district, so near seems every hill-top as almost to be touched. But as you approach their several positions, expanding valleys, deep fathomless chasms, and the channels of noble rivers, bar farther approach, and attest the wide, independent domains of each. They are monarchs every one of them—Brae-Riach, Cairn-Toul, Cairn-Gorm, Ben-Avon, Ben-y-Bourd—each holds his own regal court, over tarn, lake, and stream; torrents, cataracts, and all the appurtenances of the boldest mountain scenery.

After one has time to gather up his thoughts and perceptions, the scene resolves itself, still indeed as of one whole, but of distinct component parts. In the far distance you attempt in vain to number the peaks that everywhere rise against the sky line; but more closely around, five or six summits are seen to spring from a single root; a common circumference marks out the limits of the group; and, by no unreasonable liberty with the imagination, you easily replace the old materials into the vacant interstices, before the water had begun its work of abrasion, or the earthquake coming to its assistance shivered their solid rounded forms into these hideous, precipitous gorges and chasms. The great hills here stand, every one of them, upward of four thousand feet above the level of the sea; and when entire, one aggregated whole, as possibly they originally were, the center mass may have towered thousands more into the overhanging firmament. The scene is utterly unmatched, as it cannot be described, by any other in Great Britain: and make your ascent when you may, there are sights and objects to be met with at every step, in every salient dell, that will cause you evermore to rejoice you commenced your travels among the Aiguilles of Ben-Muich-Dhui.

It is in the great mountain groups that the true key is to be found to the science of geology, as well as all those collateral circumstances which impart so much charm to it as a healthful and invigorating exercise to mind and body. Here, amidst these piled-up masses, we are furnished with the lowest ascertained sections of the earth’s crust, from which we can at once study the nature of its rocky divisions, and the laws which prevail in the order of their superposition. When the world was in its primeval state of chaos, without form and void, we are warranted to assume that the mountains as yet had no place on its surface, but subsequently arose out of the bosom of the deep; and lifted up, as they emerged above the waters, the rocky strata already enveloping the globe. These strata are still to be seen folded round the central masses, disrupted and torn like a garment too tight for the body, and displaying through innumerable cracks and fissures the inclosed rocks. This fact lies at the foundation of all geological inquiries, gives to the subject all its pretensions as a science, and before proceeding on our “Course” a word of explanation will be in place.

The first condition of the earth, of which we have any historical notice, is that which is represented in Genesis, where, after the initial declaration that God was creator of all things, we are told of a period when the whole of its materials were as yet unarranged, “and darkness was upon the face of the deep.” The Divine Spirit moved upon the surface of the shapeless mass, when the various elements of air, earth, and water gradually assumed their respective positions. The form which the earth had impressed upon it, as philosophy has demonstrated, was that of a spherical body, flattened at the poles, a figure resembling as nearly as possible that of an orange. There is reason to believe, therefore, that every part of the solid mass of earth is symmetrically arranged, and that every individual particle occupies the position which Divine wisdom has assigned it.

Rocks, let the reader be assured, have not been indiscriminately heaped together. Everything here, amidst all the apparent confusion which surrounds us, is in the most perfect order, following one uniform law of superposition. When God fixed the foundations of the earth, stretched his compass “upon the face of the deep,” and laid “the beams of his chambers in the waters,” he completed the mighty edifice agreeably to the plan which he had determined upon “from the beginning:” the different portions of the building rise one above another in regular succession; and the work, so far as we can survey the interior, displays the several courses into which the materials have been thrown. These constitute what geologists call the strata of the earth, layers of varying thickness, such as our slates, sandstones, and limestones exhibit, and which nearly envelope the circumference of the globe. The order in which the strata are disposed is uniform from below upward, and this order is never inverted. From the blue slates of the Grampians to the Chalk cliffs at Dover, there is a regular succession of intermediate rocks, piled one upon another like the mason-work of our houses; and while to many there appears nothing but confusion, to the scientific eye every portion of the series, although the same ingredients enter into several classes of rocks, is as well defined and as easily recognized, as the two members at the extreme points are by the common observer.

But beside the stratified rocks, there is another class of rocks equally extensive, and which occupy an important place in the economy of nature. These are the granites and whinstones of which the highest mountain ranges are usually composed. There are many subordinate varieties belonging to both classes, which are characterized by slight shades of texture and composition and distinguished by different names. One thing is common to the members of each group. They are not disposed in layers, and exhibit no lines of stratification, except in the granite rarely, throughout the entire mountain chain. These rocks occupy no fixed place in the order of superposition, but seem to be intruded in the most irregular manner among the stratified rocks, separating one bed from another, filling up fissures and rents; and binding and interlacing the various deposits more closely and firmly together. They are often composed of the fragments of other rocks, agglutinated into a compound mass by a base of clay. Remarkable changes are also produced upon all the strata where they come in contact with granite and whinstone—chalk being converted into crystalline limestone—limestone into chert—clay and sandstone into a substance as hard and compact as flint—and coal is deprived of its bitumen or the quality which renders it so useful as a combustible body.

From these, and other appearances, geologists have been led to the conclusion, that these rocks are of later origin than those which are stratified, that they have been injected among them in a state of fusion; and by the expansive force of internal heat, that they have burst through the stony crust of the earth, and elevated and disrupted the strata which compose it. They are, if we may use the expression, the levers which the Almighty has employed in bringing up the lower deposits to the surface, in laying open the interior chambers, and in producing all that infinite variety in our earthly habitation which ministers to the comfort and well-being of man. Much seeming confusion and disturbance mark everywhere the course of these rocks, similar, though upon a more extensive scale, to the disorders attendant upon the irruption of a modern volcano; but throughout the whole there reigns such a harmony of purpose, that the conclusion is irresistible, these operations could only have taken place by Divine permission, and are in accordance with the Divine plan, controlling the most refractory agencies of nature, and causing them to contribute to the general good.

These eruptive rocks have been produced under the sea, at a period, many of them, when the waters and the dry land were not as yet separated from each other. They are therefore termed sub-aqueous products, and are, in consequence of the pressure to which they have been subjected, hard, compact, and heavy. They differ in this respect from the products of modern volcanoes, which are light and porous, as being formed under the simple pressure of atmosphere, and are denominated sub-aerial. The most prevailing ingredient both in ancient and modern lavas is feldspar: this, combined with hornblende, quartz, and augite, characterizes the whole of the two families of the trap and granitic rocks; and completely establishes their claim to be regarded as originating in submarine volcanoes. Geology is thus in its first step, and initial principles, in perfect accordance with the scripture record; and, in walking over the varied fields of creation, we shall tread all the firmer, and enjoy our recreations all the more, that we find the word and works of God illustrative of each other, revelation never contradicted, and science bearing enlightened testimony to the wonderful truth—that the hills melted like wax before the Lord.

Two reasons, therefore, are to be assigned for the starting point of our investigations, and the route fixed upon in following them out. This center group of mountains comprises the first or lowest phenomena connected with the science of geology: here the earliest lessons are inscribed; and here, developed on a great scale, we are presented with the axis of elevation which has given character and outline to the whole surrounding district. Ben-Mac-Dhui is the most prominent type of our primary mountains, and has been mainly instrumental in lifting up a large portion of the Grampian range. Looking abroad from its summit, over all that varied landscape of plain and valley, and further than the eye can reach, summoning in imagination before us the successive strata as they recede in the far distance, a diagram which would faithfully represent the order of the rocks and their relation and proximity to the granite, would be quite correct in making Ben-Mac-Dhui a pyramidal basis, and the other formations as steps to the apex of the pyramid.

This lofty chain of primary rocks on the one hand, and the Alpine region of Switzerland on the other, may likewise be regarded as constituting the barriers or edges of one great basin, within which are inclosed members of almost every rock formation, fossiliferous as well as non-fossiliferous, existing anywhere on the face of the earth. Along the line of tour indicated, you pass over every intermediate deposit, from below upward; and have laid before you, for inspection, specimens of all that is interesting and curious in the science. Betwixt the two points, selected as our termini, lie strata upon strata, organic bed upon bed, not piled up in one colossal mass, but drawn out and slipped over the edges of one another, and so arranged and disposed at successive intervals as most happily to suit the convenience and successive stages of the journey. This is one of the most remarkable facts in descriptive geology, whereby we learn that a depth of nearly ten miles of solid rock can be duly examined, every particle and fossil of it, not by perforation downward to the bottom, but by the natural inclination of the beds, and their several outcrops rising to the surface like the inverted tiles on a roof. In consequence of this persistent arrangement, objects, both new and strange, will at every step meet the view. There the whole system of geology, page after page, is spread out before you. Every day opens up a new chapter geographically, as well as mineralogically divided. And when you have gained the summit of Mount Blanc, you can leisurely, in the mind’s eye, look back over the whole Course of Creation.

It is a reproach, I am aware, sometimes cast upon geological researches, that the portion of the earth’s surface exposed to view is as nothing compared with the entire mass, and that another portion, by far the largest segment, is concealed by the ocean, and its own debris. In addition to these disadvantages, it may now be objected that the line of description indicated narrows the field of research still farther, and that a few disconnected materials only are all that can therefrom be extracted. It may be answered,—“That the earth is constructed with such a degree of uniformity, that a tract of no very large extent may afford instances, in all the leading facts, that we can ever observe in the mineral kingdom. The variety of geological appearances which a traveler meets with, is not at all in proportion to the extent of country he traverses; and if he take in a portion of land sufficient to include primitive and secondary strata, together with mountains, rivers, and plains, and unstratified bodies, in veins and in masses, though it be not a very large part of the earth’s surface, he may find examples of all the most important facts in the history of fossils.”[1] We shall, however, along with our lineal descriptions of the mineral kingdom, notice the occurrence, position, and fossil contents of the strata as represented in other parts of the world.

CHAPTER II.
NATURE AND STRUCTURE OF THE GRAMPIANS. PRIMARY ROCKS.

In beginning a description of the earth, every one is prepared for the information, that it must have existed in some form or other antecedent to the development of life upon its surface. Revelation asserts a succession in the objects created, as well as in all the cosmical arrangements connected with the early history of our planet. Things were not perfected at once, and brought simultaneously into adaptation and form; a preparation and a fitting up, as it were, of the inorganic preceded the introduction of the organic structures of creation; and, accordingly, the solid framework of the globe gives corroborative evidence of this anterior condition of its history. The rocks of the period are, from this circumstance, denominated Primary, because they not merely denote the absence, but are assumed to have been formed before the existence, of any types of organic matter, vegetable or animal.

Nowhere can this first lesson in geology be more forcibly taught than by an examination of the sterile rocks and rapidly decomposing precipices of this bleak and hoary region. Once through the glens, and fairly commencing the ascent of the center mountain, every symptom of existing life has disappeared; and amid the huge, tabular masses that accompany you in the upward journey, there is no trace of organic forms in these vestiges of the past. The nucleus of the whole group is granite, one dense aggregation of crystals; now rent and furrowed by a thousand seams, the heart and penetralia bared and open, a convulsed sea of molten matter still and motionless as the grave! The associated rocks, all of the primary class, are gneiss, mica-slate, quartz-rock, chlorite-slate, and limestone; and these inclose no relic of a living thing. Geology thus ascends the stream of Time; but it gives no farther tidings of a scene like this, save that it arose from the depth beneath at the Creator’s bidding.

The Structure of the District.—The mountain of Ben-Mac-Dhui, according to recent measurements, is 4,418 feet in height, and covers a superficial area of nearly forty miles in extent. It occupies a central position in the Grampian range, being about equidistant betwixt Aberdeen on the German Sea and the western coast, so ribbed and indented by the Atlantic. Ranges of granitoid rocks, of the primary class, diverge for nearly forty miles south and north of Ben-Mac-Dhui, thereby giving this mountain a prominence in position possessed by no other within the boundaries of the island.

The valleys by which this monarch is surrounded, open in every direction, and run toward every point of the compass. Two great rivers, the Don and Dee, take their rise in some of the deep gullies of the mountain, while the Spey is fed by the innumerable streams that issue from its sides. These rivers have each an easterly direction, which, by their water-shed, give shape and character to the whole district. A hundred lateral glens, with their tributary streams, and all their tarn-head or loch, debouch upon the three principal straths, whereby their deepest solitudes are reached, and the very foundations of their loftiest peaks bared and laid open. There, remote from human habitation, the geologist sees as it were two conditions of the world,—the one, the shattered framework and fragments of its early convulsions, huge mountains prostrate and crumbling beneath his feet,—and the other, the spring-heads of renewed vitality collecting in countless dripping rills, each to sustain its own little plot of pasturage and flowerets, not the less welcome that they are all so rare and alpine, and looking in their freshness as if they were there purposely to cicatrize and heal up the deep scars in the rugged precipices around.

Loch-na-gar on the south-east, and Ben-y-gloe on the south-west, have also their separate congeries of lofty hills and precipitous defiles, inclosing tarns, lochs, and rivers; likewise their own peculiar grouping of glens and straths, whose inner recesses are all most speedily attained through the velvet pathways of their moss and crow-berry. From the poetic peak the prospect is worthy of its fame. All around is a vast rolling surface of mountains, with steep mural precipices, and separated by deep ravines, while immediately underneath a cliff of 1,300 feet lies the lake, contracted to a span, and rendered even darker in its gloom by the snowy glaciers that sparkle here and there on the overhanging rocks.

From Loch-na-gar eastward to Craigdarroch and the more distant Morven, and through the great forests of Balloch-bowie, Glentanner, and Glenesk, granite is the prevailing rock. Around Balmoral, immediately under “these steep frowning glories,” the granite rises into a number of smaller and beautifully dome-shaped hills. Cloch-na-bein and Mount Battock, washed by the Feugh and the Dye, are likewise composed of granite. Gneiss, mica-schist, quartz-rock, and clay-slate hang on the southern slopes, training down into the plains of Kincardine and Forfarshire. To the west of Loch-na-gar, and intermediate betwixt that range and the granitoid masses which cluster round Ben-Mac-Dhui, the same alternating series of stratified rocks occur. From Castleton to the head of Loch Callater, and along by Glen-clunie to the junction with Glen-beg, where the counties of Aberdeen and Perth meet, the strike of these rocks is again passed over in a walk of a few miles; the beds penetrated and tilted up by veins of granite and feldspar. Several dykes of the latter mineral, of an extremely deep-red color and glassy crystalline texture, traverse the district, extending over a vast range of country, penetrating indifferently the granites and schists, and always forming attractive objects in the beds of the rivers.

In the immediate vicinity of Castleton and Invercauld, the geological phenomena of the district are very accessible as well as instructive, in consequence of the comparative smallness of the mountains, and isolated position into which they are thrown. A magnificent amphitheater of hill and plain is spread out before the traveler, through which the Dee, after a course of upward of twenty miles from its wells—mysterious as the fountains of the Nile—rolls its waters, now joined by the Quioch, Clunie, Candlie, and all the tributaries of the surrounding peaks. Some of the hills present bare precipitous cliffs, as Craig Koynach and the Lion’s Face, where the granite, schistose, and calcareous rocks are finely exposed to view. Their strike is continued westward, when they are severally crossed in the easy ascent of Morne, half of whose dome-shaped top is covered with quartz-rock, which here, as in most of the neighboring heights, attains to an enormous thickness, and shows in weathering the yellow granular texture of sandstone. So remarkably like are some specimens we picked up by the roadside, that for a time we imagined ourselves to be approaching a region of secondary deposits. Internally, however, the bright crystalline structure is uninvaded by decay. Ben-Beck, Cairn-a-drochel, and Ben-Viach behind Mar Lodge, are chiefly composed of gneiss, passing into a slaty micaceous schist. The same character of rock continues upward through Glen-lui until its junction with Glen-lui-beg and Glen-derry, where the granite maintains its sovereignty over all that primitive lofty region.

The geologist, in penetrating these primeval wilds, has but little choice left him as to the comforts of his pathway. Arrived at the top of Glen-lui, the two diverging passes, right and left, are equally desolate, savage, and grand. He may make his selection as the feeling of the moment prompts, but he will not be able to congratulate himself as the traveler in a different field—

Hic locus est, partes ubi se via fundit in ambas:

Dextera, quæ ditis magni sub mænia tendit;

Hac iter Elysium nobis: ut læva malorum

Exercet pænas, et ad impia Tartara mittit.

No “fiends,” indeed, as Dryden renders it, are here, unless the belated traveler may allow his fancy to shape these gnarled withered stumps of the old forest, as it well may, into grisly living forms; or the red deer breaking from their coverts, and gazing in wild amazement from the crags, startle him from his propriety. Still Loch Avon, black as pitch, and imbosomed in horrid rocks, is not an unfitting emblem of the Tartarean lake.

Pursuing his route to Strathspey, either through the desolate openings of Ben-Avon, or by the wild passes of Brae-Riach and Cairn-gorm, the geologist again drops down among the gneiss, schists, limestone, and quartz. These types of rock line the trough of the Spey, on both sides, as far as the granite district of Ericht and Laggan, presenting the usual phenomena of granitic and feldspathic dykes, and in some places, as at Loch-an-Eilan, remarkable twistings and flexures in the mica-schist around this eagle-haunted lake. Glen Tilt, on the south-west, is distinguished by a singular display of granitic veins, appearing to radiate from a common center—the well-known phenomena which the philosophers of the Hutton and Playfair school pressed so keenly and successfully into the service of their theory. The gneiss is generally to be observed in the form of low ridges, interstratified with quartz-rock, and approaching in mineral qualities to the mica-slate.

The bearing of all these stratified rocks is, on the main, sufficiently indicated by the outline of the Grampian range. The quartz, mica, and chlorite slates, are nearly continuous along the chain, traversing in a S. W. by N. E. direction the breadth of the island, from sea to sea. The line of strike, however, is often interrupted, either by the eruptive veins above mentioned, or by the upheaval of the central axis, which, as it rose with greater violence, or was parted into higher and unequal ridges, would necessarily occasion corresponding changes in the lie and direction of their coverings. This principle in geological dynamics has been satisfactorily established by Mr. Hopkins of Cambridge, who has shown, that in the production of any great line of elevatory disturbance, whether affecting straight, curvilinear, or ellipsoidal masses, the strata would frequently be broken by fissures at various angles to the chief line of strain or elevation. Hence these interminable glens, transverse straths, cul-de-sacs, and countless depressions, forming tarns and lochs, all inosculating into each other, and which give such variety and grandeur to this alpine region. The pent up ebullient matter beneath the crust would thereby force its way to the surface—now in the form of veins—now in long narrow ridges—and in other quarters assuming the contour of broad mountain domes. The dip, in like manner, corresponding to these partial strikes, as well as great axis of the chain, is often various—as at the Linn of Dee, and along the braes of Corry Mulzie, the beds being almost horizontal, while generally they are so highly inclined as to be nearly vertical.

There are also numerous examples where the crystalline strata dip inward toward the granite ridges, and in this manner form an acute angle with the base, instead of being infolded over and welded to them. The only admissible explanation in these instances of the dip is, that the ends of the strata adjacent to the eruptive masses have sunk into depressions occasioned by the evolution of igneous matter, while their upper edges have been tilted backward. Hence the schists often rise into independent elevated crests all along the chain, and even where no granite appears at the surface. The rocks in Glen-Beg and Glen-Clunie afford examples of this kind, where, as in Cairn-na-well, and the other mountains here, they are highly inclined, and plunge in the direction of the principal range. Geology, viewed in this light, becomes an auxiliary to physical geography, explains many anomalous appearances on the earth’s surface, and successfully accounts for all the flexures, breaks, undulations, and inequalities, that constitute such marked features in the primary strata.

Until very recently, the doctrine maintained was, that nearly all the inequalities on the earth’s surface were produced by the erosive and denuding effects of water; that not merely the small lateral valleys and branches of rivers, but likewise all their main trunks, were caused by the slow and gradual working of the stream, cutting the most solid and massive rocks in the same way and almost with the same instrument by which the lapidary divides a block of marble or granite. Nay, with such a ready agent, acting through incalculably remote and indefinite periods of time, the conclusion was arrived at, that “on our continents there is no spot on which a river may not formerly have run.” A sounder philosophy, and one far more accordant with the facts, is now beginning to prevail, namely, that nearly all transverse gorges, by which rivers escape across ridges from one water basin to another, are nothing more than ancient apertures in the crust of the earth, which have resulted from the former disruption and denudation of the rocks: and that rivers, properly so called, have never cut sections through chains, but simply flow in chasms prepared for them.

Nature and Qualities of the Rocks.—The granite is the most prevailing, as well as the most striking in its appearance and texture, in the whole range. Mineralogically considered, every specimen is a gem. Granite is a compound, aggregate rock, here of a lively flesh or rose color, consisting of perfectly formed crystals of quartz, feldspar, mica, and in some instances hornblende, when it merges into what is termed syenite. The sparkling film is mica. It is not metallic; but it shines with metallic luster; and in some places of the chain, as at Rothes on the Spey side, it is found in plates so large as to become a substitute for glass. The component parts of mica are silex, alumine, potash, iron, manganese, and traces of other substances. The colors of the mineral are various, according to the proportions of some of the ingredients. The laminæ are divisible into plates no thicker than 1/300,000th part of an inch. Entering into the composition of almost every rock from the oldest to the newest, it abounds chiefly in granite and schist, but also occurs in sandstones, and the slaty shales of the coal formation.

I never look at a piece of granite, fragments of which are strewed on every heath, without being reminded of Paley’s inaccurate and disparaging comparison betwixt “the stone” and “the watch,” in his celebrated argument for the existence of Deity. Take a specimen fresh and living from the rock, or from any bowlder that meets you on the way. There is not a stain in all that composite mass: how bright every ingredient! No workmanship of man can rival it in its closeness of texture, beauty of color, distinctness and delicacy of shading and outline. What chemistry elaborated these particles as they separated and united? What scales weighed their impalpable elements? What hands constructed their nicely harmonizing proportions? Whence derived their principle of cohesion as they cooled and inosculated in the burning crucible? As that fragment of rock, so is the whole interior of the mighty range—the whole basis of the continents of the world—countless myriads of sparkling gems wrought into symmetry and form; the foundations of our earthly habitation literally “garnished with all manner of precious stones.”

Paley, forgetful of every law or purpose so conspicuously developed in the whole of these beautiful arrangements, thus commences his great work on Natural Theology:—“In crossing a heath, suppose I pitched my foot against a stone, and were asked how the stone came to be there, I might possibly answer, that, for anything I knew to the contrary, it had lain there forever: nor would it perhaps be very easy to show the absurdity of this answer. But, suppose I had found a watch upon the ground, and it should be inquired how the watch happened to be in that place, I should hardly think of the answer which I had before given, that for anything I knew, the watch might have always been there.”

How many fallacies are there in this statement so far as mention is made of the stone? The science of geognosie, not so far advanced in Paley’s time, now clearly establishes the “absurdity” of supposing its having lain from “eternity” in the place where it is found. The relative ages of mountains, and therefore their succession in Time, are now demonstrable and well understood. Then, the component parts of the mineral are as well defined, as accurately proportioned, and arranged in manner and order as precisely, as the several parts of the watch. The mica, the quartz, the feldspar, have each their law or order of structure, as well as their principle of aggregation; and they have taken their respective forms and no other, and have assumed their compound structure and no other, in obedience to chemical affinities and an atomic adjustment, as certain and unalterable as are the conditions and requirements of dynamics.

Nay, more, the parent rock, from which that stone was taken, has its own place in the system; its position, amidst the upheaved disrupted strata around, has been assumed for a purpose; and the very size, form, and outline of the giant mass, are all shaped to an end. Rocks are as easily distinguished as trees or animals, which have not risen up by accident, but have been constructed out of certain materials, and arranged each according to its own class. Their internal characters, and even outward shape, are marked and defined. The gnarled oak in fiber and texture differs not more from the soft, pendulous, graceful willow, than are the differences of rocks and minerals in their normal arrangement of particles; in their diversity of fracture, cleavage, luster, and density. We see at once the mechanism of the watch, the growth and expansion of plants and animals. But so, upon gaining the least knowledge of its frame-work and structure, we cannot open our eyes upon any part of the external world, without being impressed with the conviction, that all which we see and admire, must be the work of a higher power. Design is stamped upon everything. Will, order, and might are everywhere visible.—Geology, discovering harmony amidst apparent confusion, renovation in decay, shows that every rock is fitted to its place; that systems and series of formations are arranged upon a principle of utility; and so thoroughly calculated to exercise their assigned functions have all the parts been formed, that the most elaborate machinery of man’s contrivance falls infinitely short of the beauty and perfection everywhere displayed in the material creation. Lain forever! No; such a scene of mountain, valley, river, plain, and ocean—all related to each other—does not exist by chance, is not conserved nor arranged by accident.

Theory of Formation.—When we examine a piece of granite, nothing appears less likely, to a common observer, than that it was once in a molten state through the action of fire, and that its crystalline structure was assumed in process of cooling. Now, the fact of its crystallization, the beautiful and perfect arrangement of its parts, the impress of the one crystal upon the other reciprocally communicating their respective shapes to each other, and the compact, agglutinated state of the whole, is regarded as the strongest proof of the igneous origin of this remarkable rock. Granite is not a mere congeries of parts, which, after being separately formed, was somehow brought together and united; but it is certain that the quartz, at least, was fluid when it was molded on the feldspar. In some granites, the impressions of the substances on one another are observed in a different order, and the quartz gives its form to the feldspar. The ingredients of granite were therefore fluid when mixed; and this fluidity was not the effect of solution in a menstruum, as in that case one kind of crystal does not impress another, but each retains its own peculiar shape; and the conclusion is, that they crystallized from a state of simple fluidity, such as, of all known causes, heat alone is able to produce.

This is the account given in the Huttonian theory, as expressed nearly in the words of Playfair, which, along with the position of veins, the disruption of superincumbent strata, and other phenomena, has resulted in the universally received admission of the Plutonic character of this class of rocks. Dr. Macculloch has extended the principle, and has satisfactorily proved, that granite is but one term in the series of igneous products, the passages from which are distinctly traceable into granitoid syenite, and syenitic greenstone, and thence into greenstone, basalt, and lava. Professor Forchhammer considers granite, when melted, as one simple compound, and which only on cooling becomes separated into the different minerals that compose it.

Granite, wherever it is found, is inferior to every other rock; and as it composes many of the greatest mountain chains, it has the pre-eminence of being elevated the highest into the atmosphere and sunk the deepest under the surface, of all the mineral constituents of the globe to which our researches extend. The associated primary rocks in this upland region overlie the granite, and possess a distinctly stratified structure. They are not now in their original position. They have been tilted up, traversed, and interlaced by the granite while in fusion, and have been altered greatly in their texture and qualities by their contact with the heated mass. Hence they are called Metamorphic Rocks, because of the change to which they have been subjected.

The rocks that immediately overlie the granite are gneiss, mica-slate, quartz-rock, and limestone. They all partake of the crystalline structure, and all, except the last, possess the same ingredients, and assume interchangeably the same aspect. Of gneiss there are three varieties, each composed of feldspar, quartz, and mica, and distinguished by the size and form of the crystals that constitute the mass. This rock, consisting in all cases of thin lenticular plates, has a ribbon-like appearance, and, according to the predominance of one of the parts, becomes glandular, slaty, or aggregate. Mica-slate consists of quartz and mica—the latter predominating—and feldspar frequently entering as an adjunct. Quartz-rock, as the term implies, is formed of the pure siliceous matter, nearly homogeneous in many instances—but scales of mica are often present—and feldspar not always absent. The limestone, again, differs from all the above in the excess of the calcareous element, while, along with talc, steatite, actynolite, asbestus, and other simple minerals, mica, quartz, and feldspar are likewise to be numbered among the imbedded crystals. These rocks, over the entire surface of the globe, are of one family, and generally associated. They are always the lowest of the stratified series, and follow in the order now described. They are essentially one and the same in their constituent mineral qualities—different in the form and proportions in which they are aggregated—and geographically connected with the granite in their distribution. Thus these crystalline rocks not only constitute the floor of our earth, but have in all probability supplied the materials under whose plutonic agency, when fused and molten, the massive pavement was raised above the waters and tempered into its present consistency.

Granite, the derivative rock, is found, accordingly, in every region of the globe—the lowest as well as the most universally distributed—the basis as well as the apex of every great mountain chain. No true Highland scenery is anywhere to be found that does not embrace granite as the most prominent feature in the picture. Not a hill in Scotland, two thousand feet high, but incloses a portion of this rock. The beauties of the English lake country are all derived from this source. The lofty serrated peaks of Wales have been raised upon its crystal foundations. The north-west and central portions of France, the Swiss and Tyrolese Alps, the vast expanse betwixt Dresden and Vienna, the Caucasus, great part of the Himalayan, Uralian, and Altai mountains, and large elevated districts in China, are all less or more of granite formation. Through Northern Russia and Scandinavia the granite may be regarded as merely a continuation of our Scottish range—one great stony girdle, which forms the primary mineral boundary of Northern Europe. America, Africa, Australia, possess not a single ridge of celebrity through which the same fundamental rock is not traceable in every district. How simple, uniform, universal the component elements of the globe! One and the same atmosphere surrounds it, one ocean washes it, one system of massive pillars supports it, one sun enlightens it. How direct and irresistible the inference, that one intelligent, all-powerful Being fashioned and framed it!

The separation of the dry land from the waters was, doubtless, effected through the instrumentality of means. The igneous theory of granite, and other amorphous rocks, is in accordance with this supposition, which thereby imparts a sacred and peculiar interest to all our investigations respecting the origin and elevation of mountains. The range of geological investigation is thus wide as the circumference of the globe—deep as the foundations of the earth—and sublime thoughts are everywhere awakened of Him—

Whose dwelling is the light of setting suns,

And the round ocean, and the living air,

And the blue sky, and in the mind of man:

A motion and a spirit that impels

All thinking things, all objects of all thought,

And rolls through all things!

CHAPTER III.
THE SILURIAN SYSTEM. FIRST TRACES OF LIFE.

The group of rocks on which we next enter are termed fossiliferous, that is, there is contained in their hard stony substance the impressions and actual remains of organic bodies. As we proceed upward through the series in their ascending order, we will find different rocks distinguished by different classes of fossils, and characterized by distinct lithological appearances. They are in consequence divided into different formations, and called by particular names. Hence the origin of systems, of which there are five or six recognized by geologists, separable into their respective groups of strata. Descending from the primary, the highest as well as lowest in the series of rocky combinations, the group which first invites attention is the Silurian; so denominated because the strata are widely spread over the districts in England and Wales, anciently inhabited by a people called the “Silures.” They are found in various quarters of the world, and occupy a large area on the southern frontiers of Scotland.

The rocks of this class consist of a group of argillaceous, calcareous, and arenaceous deposits, varying in color and texture. They are of great thickness and severally impressed with their own written story, the fossil memoranda of the changes and events that occurred betwixt the formation of each. These are the transition rocks of Werner. The newly-adopted term of Silurian implies no peculiar theory as to their origin. It simply expresses the fact that in the district in question a complete succession of fossiliferous strata is interpolated between the oldest slaty crystalline rocks and the old red sandstone. The system is divided by their discoverer and historian, Sir R. I. Murchison, under the ascending series, into the Cambrian System, Llandeilo-flags, Caradoc Sandstone, Wenlock Shales and Limestones, and Lower and Upper Ludlow Rocks.

Do the equivalents of all, or of any, of these groups exist in the Grampian range? Geologists for the most part have been answering these questions in the negative. Hitherto no true silurian deposits have been recognized as existing among the northern Scottish mountains, and no well-authenticated organism of the system has been detected in any of their localities. This, however, will hardly be taken as a conclusive argument after the admission into the family of the Skiddaw slate, in which the faintest traces of organized matter have only very recently been observed, while the over-lying series consisting of chlorite-slate, and alternating beds of porphyry and greenstone, from twenty to thirty thousand feet thick, have not yet been proved to contain a single fossil. “Good fossil groups,” Professor Sedgwick argues, “are the foundation of all geology; and are out of all comparison the most remarkable monuments of the past physical history of our globe, so far as it is made out in any separate physical region.”

We are convinced that the clayslates and graywackes which repose on the southern flank of the Grampians, as well as abundantly in the interior, will, upon strict examination, have their place assigned among the Silurian class. Mr. Nicol, who has done so much for the Lammermuir deposits, will find ample scope for his investigations, and all his ingenious speculations, in determining the true position of these argillaceous beds, which are of prodigious thickness and vast extent. This is not the place to enter into details, but in support of the view now advanced, the following among other reasons may be given.

First of all, the clayslate of the Grampians resembles in its lithology the slates of Wales and Cumberland, admitted to be silurian. In hand specimens they cannot easily be distinguished from each other: practical men consider the slates of Dunkeld and Glenalmond as softer and less flinty than those of the south. They pass from extremely coarse into the finest grained varieties, when the graywacke character is entirely lost in the homogeneous mass. Their position in reference to the crystalline rocks, in the next place, is very distinct, never alternating with, nor lying conformable to, either the gneiss or mica-schists. They form the outer zone, from east to west, of the Grampian range, where feldspar, porphyries, and trappean rocks are along the whole line mixed up or associated with them. Then overlying the clayslate, precisely as in Cumberland, the old red sandstone is found in immediate succession and resting unconformably. Shall we add that, even in a topographical point of view, these beds will be admitted to vindicate their claim to Silurian origin, constituting, as they do, in extension, a portion of the great primary belt that encompasses the western shores of Great Britain, and beyond the channel, stretches through Brittany and Normandy?

From considerations such as these there are sufficient grounds, we think, for constituting the clayslates and porphyries of the Grampians into a “physical group,” existing in a “separate physical region.” The absence of organic remains may be accounted for by the fact of the vast disturbance prevailing in the seas at the period, and indicated by the prodigious quantity of igneous matter spread repeatedly over their bottom. These causes would act in so far in preventing the existence and increase of living things, over all these parts, and most certainly in obliterating the traces of their remains, if any were deposited. But as future explorers may yet detect them in abundance we proceed to consider the nature and classes of fossils elsewhere discovered in the Silurian strata.

Animal Remains. Here, in this series of rocks, we are carried back to the beginning of life upon the globe, in which we see the very dawn and commencement of earthly enjoyment, the first forms and races of creatures which were privileged to eat at the banquet of creation. As matter of history, therefore, nothing can be more interesting; as a subject of mere curiosity concerning ancient relics, the most ardent archæologist will be amply gratified; and as showing the manner of the divine actings in replenishing the earth with living things, the word and the works of Deity are again to the devout inquiring mind brought into pleasing harmonious comparison.

We find that the creatures belonging to this first epoch of organic existence are, generally, low in the scale of animated being. The rocks in which their remains are imbedded are, in some instances almost entirely composed of organic matter, showing that life at first was not bestowed sparingly, or, through some hidden mysterious processes, stealthily introduced upon the stage; it rather appears in an abundance and variety, speaking of a purpose in obedience to a designing creative act. As suitable to the condition of the planet, not at once but by successive arrangements brought into a state of adaptation for sustaining life, the animals now formed appear to have been chiefly of the invertebrate division, that is, animals of comparatively simple structure, destitute of a bony skeleton, suited to live in shallow waters and muddy bottoms, and to be content with such fare as an infant state of things over the young earth could produce. Among these ancient families are graptolites,—many of them zoophytic bodies, allied to the modern sea-pen; crinoids, or lily-shaped animals, of beautifully-developed forms; and trilobites, crustacean creatures divided into three dorsal lobes. There are several species of each. And so accurately has nature adhered to her plan of operations, that we find the corals of that early age doing the same offices, and piling up similar submarine reefs, by which these busy little architects are still distinguished. The mollusca of the period are very numerous, embracing almost every order and form of shell that are found in our present seas, though wholly of different species; conchifera, brachiopoda, gasteropoda, cephalopoda, pteropoda, beside the heteropoda, of which there are no existing analogues. The habits of all these orders must have been nearly the same as those of our modern types. The cephalopoda, embracing the nautilus and orthoceras tribes, were then as they are now, the tyrants of the deep, furnished with eyes and ears, and armed with powers that enabled them to roam and prey at will in the bays and estuaries of the primeval world. There have been named and catalogued of these first forms of the moving creatures of the deep about three hundred and fifty distinct species.

But, beside these, there have been discovered in the silurian rocks six or seven genera, involving a still greater number of species, of fishes of the order of the Placoids, so denominated from the broad scales or plates with which they are covered. The probability is, that more of these higher organisms will yet be brought to light, as all the strata of the system consist of marine deposits, and only the most limited sections have anywhere been explored. They constitute the lowest of the fossiliferous beds; are generally found, except in Russia, in a vertical or highly inclined position, and consequently but little of their superficial area is exposed. Here, however, geologists have named and described an Onchus Murchisoni, a Thelodus parvidens, and other four genera of equally erudite-sounding names. The onchus type is continued, and greatly multiplied in species, in the two succeeding formations, when it dies out, or at least no trace of the genus is found in later times; while the rest appear to come and to depart within their own geological epoch. These organisms are all as yet termed Ichthyolites, that is, simply fossil fragments of fish, as no entire animal has been anywhere detected, while of their true class M. Agassiz affirms with confidence. Teeth, fins, spines, occur so abundantly in a stratum of the Upper Ludlow series in Wales as now to be termed “the bone-bed,” giving assurance that the seas were thus early stocked with the finny tribes. The families of most of these fishes have yet to be determined. But nature, though in her operations “simpler than man’s wit would make her,” was still pretending enough to be shaping out thus early the higher types of life.

The science which introduces to such sights and studies, occupies no mean place among the various branches of human inquiry. To neglect to decipher what is so indelibly recorded on these pages of creation, is willfully to shut oneself out from what has been actually preserved for information—a voice from the past, which speaks in the same distinct articulate language as the present of the fiat of Omnipotence. No object is mean or contemptible which divine wisdom has formed, and no subject is unworthy of investigation which illustrates His ways and works during any period of creation.

The mind, at this starting point of life, is curious to know what amount of information can be obtained as to the organic structure and specific characters of these first denizens of earth, so as to compare them with the forms and species of the analogous families now existing. The information derived from this first chapter in palæontology, we believe is, that the earliest specimens of organization are as perfect as the latest, each after its kind; and that, in these morning-days of existence, nature at once stamped, with her plastic hand, her lineaments of beauty and adaptation on everything she made. There is nothing omitted to be afterward supplied—nothing formed defective in a single part or organ that requires to be corrected. The first discoveries in geology at once speak conclusively of a plan or course of creation derived from the beginning—a power, not delegated, but linked forever with the first intelligent cause—a world, through all its changes, continually presided over and ruled by Him who made it.

Vegetable Remains were long wanting, and sought for in vain, to complete during this period the picture of the ancient world, as described in the pages of revelation. Geology, indeed, had everywhere sternly held back the required evidence, and animals were announced to be the first of living things. This, though contrary to all analogy with regard to the conditions of animal subsistence, was generally received as a well established dogma; and the earliest book of history was laid aside, or its statements in these circumstances regarded as irrelevant. Vegetable remains, however, have been detected in the oldest fossiliferous group of rocks, and this apparent discrepancy has been forevermore disproved. Fucoid plants are found in great abundance in the transition series of Scandinavia as well as in the silurian strata of our own island. That they are not more widely distributed is satisfactorily accounted for by experiments which show that some species of plants entirely disappear in water. A productive flora, therefore, may have existed from the earliest period, but, unable to resist decomposition, all traces thereof have long disappeared from the tablets of the earth.

Nay, so abundant in some quarters of the globe has vegetable matter been at this period, that there are traces of beds, approximating to coal, entirely composed of it, and the rocks inclosing these beds so charged with bitumen and carbon as to be used as fuel. “The silurian strata of the Scandinavian peninsula and the Island of Bornholm, contain,” says Professor Forchhammer, “in their oldest parts, large beds of aluminous slate, which is used in a great number of manufactories for making alum; and this aluminous slate has the great advantage over those slates of the carboniferous system of Germany and a part of France, that it contains the sufficient quantity of potash which is required to make alum.” It is well known that potash constitutes an ingredient in most vegetable bodies; and that when a plant is burned there remains a skeleton of this substance. Hence, possibly, the origin of the potash in the alum slate. But the argument does not rest upon inference. The same authority relates, that in Bornholm and in Scania, the southernmost part of Sweden, this slate contains a great number of impressions of a fucoidal plant, of which Liebmann has given minute botanical descriptions. Then, pursuing his interesting tale of this first flora of creation, he says,—“According to Professor Keilhau, Professor Bock, and M. Esmark, the same ceramites occurs frequently in the aluminous silurian slate of Southern Norway. Recently M. Hisinger has figured an imperfect specimen of it from Berg, in the province of Ostergothland, in Sweden. Thus this fucus appears to be characteristic of the alum slate of Scandinavia: and I can scarcely doubt that the most characteristic properties of the alum slate, as depending upon its carbon, its sulphur, and its potash, are derived from the great quantity of sea-weed which has been mixed up with the clay, and whose carbonaceous matter so affects the whole rock, that the slate is used as fuel for boiling the aluminous liquor, and burning lime; and in some parts of the province of Westergothland in Sweden, even small courses of true coal occur. There can hardly remain any doubt that this coal is derived from sea-weeds, of which fossil parts have been found, for not the slightest trace of land plants has ever been discovered.”

These are instructive facts, yet greatly to be extended, when, we question not, the land will also contribute of its flora to complete our knowledge of the most ancient fossiliferous strata.—But recently, bands of true coal have been discovered completely inclosed in this group of rocks near Oporto, the town of which stands on a ridge of granite, four or five miles wide, with mica-slate and gneiss resting on both sides. To the eastward, these again are overlaid by sedimentary rocks, chiefly clayslate; which, commencing on the coast about thirty miles north of Oporto, run down and cross the Douro, about sixteen miles above that town.—To the south of Vallango, the strata overlie a deposit of anthracite in several beds, some of them from four to six feet thick.—This coal is now worked in several pits, and principally sent to Oporto. Along with it are beds of red sandstone and black carbonaceous slates, with vegetable impressions too indistinct to be determined, but strongly resembling ferns of the coal measures. In the shales above this coal Mr. Sharpe, the discoverer, found many fossils, as orthides, trilobites, and graptolites, most of them new species, but others well known in the lower silurian rocks of Northern Europe. It would thus appear that the coal deposits of Oporto are included in the silurian formation, and are far below the usual level of the coal.

We cannot overvalue the theoretic importance of these discoveries, which do not indeed bring to light any exuberant variety of the vegetable tribes, such as the earth afterward threw out of her affluent bosom. But they mark sufficiently the period when plants, according to the geological reading of the history, first make their appearance on these lithological pages: fucoids and algæ are there in abundance, to give the vegetable portion of the narrative, as trilobites and molluscs form unquestionably the predominating features of the animal department. The coal-beds of Oporto—should their position turn out to be truly defined—show the dawning of a terrestrial flora, not sparingly but luxuriantly developed: and thus the silurian period may be regarded throughout as sufficiently characterized by well-marked types of vegetation, more doubtful in the higher forms, but determinate in the acotyledonous and cryptogamic tribes which prevail indifferently from the lower to the upper beds of the system. Nor do we require to overstrain the statement, by questioning nature or revelation as to the species, genera, orders, and classes of vegetables referred to in their respective pages. They are coincident as to the great truth itself, that Plants did exist in the earliest “days” of the earth’s history. As a science, nothing is taught in the Sacred Record. None of the technicalities of physical inquiry are employed. But a beautiful progression, and elimination of one thing after another, are intimated. The light is separated from the darkness. A firmament is set in the midst of the waters. The first plant that burst from the soil had thus every element provided which its nature and habits required—the light, to which it turns and ever yearns after—the air, in which to perform its respiratory functions—the water, from which to secrete the juices of circulation—and a dry land, out of which to elaborate materials for its structure. This is a Wisdom which is above all philosophy, instructing in the elements and principles of things, long before botanical arrangements were dreamed of, or “bushy dell” there was, where

“hoary-headed frosts

Fall in the fresh lap of the crimson rose.”

The silurian group of rocks is very widely extended, as in Britain, France, Russia, the north-west of Asia; in South Africa, North and South America, the Falkland Islands, and Australia. The most ancient physical features of the Old World can almost be recalled, as we thus trace the outline of the deposit, marking out, by its geographical distribution, the primary islands and mountain peaks of the aboriginal land. How changed the very face of things—continuity between states and kingdoms where seas now roll—and all the great continents occupying the sites over which the waters held unbounded sway!

Trilobites of the Silurian System.

CHAPTER IV.
THE DEVONIAN SYSTEM, OR OLD RED SANDSTONE.

A geologist requires not, like the tourist, to be told of the various conflicting roads that run among the mountains, in what precise course he is to wend his way. He will follow his own pathways, roads of nature’s forming, guided by the strike and lie of the rocks rather than by the beaten tracks of every-day life. But come whither he will—through Glentilt, Glenericht, Glenbeg, and the Spittal, Glenisla, and Clova,—or along the Dee, the heights of Glentanner, and penetrating to the sources of the Esks—sure we are, when he reaches by any of those passes the frontiers of the Grampians, he will pause and gaze wistfully, thoughtfully, admiringly, ere he descends, upon the magnificent prospect that stretches before him, unrivaled by any on the terraqueous globe. The Gran-pen, celticé, the shelvy or precipitous summit, Romanized into Grampius, has its own inner charms, peaceful rock-girt valleys where princes dwell, and happy as Rasselas ever trod.—And escaped from these, what an outer world beneath, fertile, abundant, replete with everything that can charm the eye or interest the student. Looming in the far distance, the Lammermuirs, of silurian origin, can just be descried as a dark-blue line on the verge of the horizon; the Ochils and Lomonds, of carboniferous age, repose like islets on the pendant sky; while, in the foreground of the picture, there is the most charming variety of woodland, meadow, farmstead, town, and mansion, all as I now gaze upon them in their autumn coloring, invested with a Claud-like mellowness that speaks with a moral yet romantic sympathy to the heart. The round tower of Brechin, the moldering walls of Edzell, the frowning battlements of Glammis, the worn-out and now verdant ramparts of Dunsinane, have each their crowds of visitants, and are all within the compass of a single day’s journey.

The eye of the geologist is in search of another object as it wanders over that lovely scene: Kinnordie, the birth-place of Sir Charles Lyell, must ever be classic ground in the history of our science. It rests on the old red sandstone, and furnishes some of the most valuable illustrations in Sir Charles’s early sketches. What influences, may we here ask, gave being and shape to the ingenious and splendid generalizations of this accomplished geologist? Is it too much to assume that the philosopher, as well as the poet, is all his life-long captive to first impressions, that the scenes of his boyhood claim “a local habitation” for many of his future speculations, and that his most matured trains of thinking have been dependent upon casual circumstances? Born and educated in the shadow of the Grampians, who can doubt that the spirit within was early stirred to lofty views as he gazed upon their elevated forms, and wondered how their peaks rose so high in air, and were thus lifted above the valleys? May it not be presumed, though the philosopher himself may have no recollection of the matter, that his speculations regarding the alternate elevation and depression of land and sea had its germ in some such happy moment of mountain inspiration? Byron owned the influence in all its power, when, in the rocky defiles and dark pine forests of Lochnagar, he had early communings with spiritual beings, the wreathe-forms and kelpies of the streams; and in visions imparted amidst the wilds of the Dee, prepared his mind for the daring flights of the Alps. The geologist had here all the materials of after-thought, which in his various essays and works he has so skillfully expanded—from his explorations of Bakie-loch with its alluvions, peat, marl, shells, and horns, in which he had the type of some of his Alpine tertiaries—the old canoe and ripple-mark here too, the representatives of their far-sundered ages and onward to his bold speculations on the elevatory hypothesis, of which the Grampians, as well as Sidlaws, supplied him with ample illustrations.

The descent from the mountains upon the series of rocks that occupy the plains, is one not merely of space, but likewise of time. A geological epoch has vanished, and a new order of things has been called into existence. This implies a change in the animal as well as in the mineral kingdom. The change may not have been sudden, but it has been thorough and pervading, accompanied by circumstances that show a general shift in the sea-bottom, and causes that have been nearly uniform in their operation over the surface of the globe. The shift in the sea-bottom is detected in the elevation of the silurian group of rocks, which have been lifted from a horizontal into a highly-inclined position: in some instances they are nearly vertical; and in most cases where the igneous rocks occur, they are bent and twisted, greatly altered and disrupted, by the process of upheaval to which they have been subjected.

Geology notes in this an epoch or age of organic existence. The superjacent series of rocks are seen lying unconformably upon the silurians, that is, the older series had been consolidated and upheaved, and a period of intervening time had elapsed before the deposition of the newer. The fossils imbedded are likewise distinct and peculiar—one and the same over the superficial area of the globe—and thus we learn to mark the great and interesting cosmical changes which had already begun to be effected. We are now among the Old Red Sandstone, or Devonian system of rocks, so denominated from their great development in that district of the sister kingdom.

As contrasted with the former system, the rocks of this period indicate considerable disturbance in the waters of the ocean, currents and agitations widely prevailing, and perhaps also deeper seas. The crust of the earth was still rising, and the mountains becoming higher, and these effects would necessarily follow. A superior order of animals were introduced. The fishes, which begin to appear in the upper beds of the silurian group, are now increased both in numbers and in variety of structures. The invertebrata were the prevailing types of the former age. The old red sandstone is pre-eminently characterized by the vertebrata, when, completely adapted to the element to be inhabited, mailed and plated over with thick horny scales, huge bony heads, fins and tails of corresponding strength and size; the Sauroid family appear upon the stage, capable all of buffeting the waves and fulfilling their destiny amid the greatest commotions. The fish of this early period are generally well preserved, even better than those of the tertiary age, in consequence of their osseous scales being harder than the bones, and which, from their interlocked arrangement, have contributed to preserve the general form of the body when the inner skeleton has disappeared and every other part and organ have been destroyed.

The old red sandstone formation is very extensively distributed in the northern counties, forming a great belt round the coast from Caithness-shire to Aberdeenshire, and consisting of three well-marked divisions, the lower, middle, and upper series of beds. The strata flank the northern walls of the Grampians and their out-liers, traversing the great central or Caledonian valley for a hundred miles, and training round the western coast by Oban, the shores of Mull and Morven. They are of great thickness in many places; and in some of the beds, as at Cromarty, Lethen-bar, and Gamrie, contain nearly all the fossils peculiar to the formation.

The order of Ganoid fishes, which afterward fulfill so distinguished a part in the kingdom of nature, is wholly absent from the silurian group, while, in the Devonian, nearly thirty genera, and considerably above sixty species, have been described and named. The scales of these creatures would appear to have been richly ornamented, enameled, and shining, and hence the term Ganoid applied to the order. In the northern districts, beyond Ben Mac-Dhui, the following genera, with several species belonging to each, have been found, namely, coccosteus, cheiracanthus, cheirolepis, dipterus, diplopterus, diplocanthus, glyptolepis, osteolepis, pterichthys. The principal localities of these fossils are—the Dipple on the Spey, Tynet Burn in Banffshire, Seat-Craig near Elgin, Altyre on the Findhorn, Clune, and Lethen-bar in Nairnshire, Gamrie, Cromarty, and various places in Sutherland and Caithness. Shetland is chiefly composed of the old red sandstone, which yields abundantly the fossils peculiar to the deposit. The formation extends through the Orkney islands, inexhaustibly fertile in organic remains, and among which have been found plates and fragments of the Asterolepis, the largest of all the genera belonging to the period: the head and jaws, at least, appear to have been of enormous dimensions, and portions of the inner skeleton must have been bony, contrary to the general cartilaginous structure of the class. The Placoids of the subjacent rocks have many resemblances to the cestracions, centrinæ, and spinaxes of our present seas, their scales being set like plates at irregular distances over the body. The Ganoids, on the other hand, whose scales were continuous, and enveloped the entire animal, have no affinities to any living types.

Specimens of vegetable organisms are very common in some of the flagstones of Orkney, resembling, in some instances, the Lycopodiaceæ, or club-mosses, so abundant in the carboniferous strata: and branching fucoid plants, of which portions have been found from two to three feet in length, and of nearly the same diameter of stem throughout. But in tracing the course of creation in this department of her works, the most important fact to relate is, the discovery of a coniferous lignite, imbedded in the old red sandstone of Cromarty. This interesting relic was obtained from these beds, several years ago, by Mr. Miller; and, though still of that remote age an instantia solitaria of its kind, like the foot-print of Robinson Crusoe, it is the sure token of a race that inhabited the island, and harbinger of a luxuriant flora then waving along the shores of the boundless waters. These northern localities, on the mainland, as well as in the islands, are also remarkable for their shell-beds in this deposit, while very few of such organisms have yet been detected in any of the Scottish rocks of the system to the south of the Grampians. The relics are confined to one species of shell, resembling in general appearance the form of the Cyclas, and are found in various quarries in the district.

What a revolution in letters, knowledge, and civilization since the days of the Romans! This, their Ultima Thule! and a science in the very rocks of which they never even dreamed. Proud they were of their fabled origin from the twin boys suckled by the wolves. Here are the spoils of ages long anterior to their myths of remotest genealogy—families of creatures that had fulfilled their destiny—buried in the sand, and upheaved into lofty mountains, while the Seven Hills of their proud city slept beneath the waves.

We now proceed to trace the order of the formation southward of the Grampian chain.

1. The conglomerate, a deep red and well-marked deposit, skirts the base of the mountains, and in some places is of vast thickness, betwixt Stonehaven and Blairgowrie. This rock is composed of fragments of the primary series, gneiss, mica-slate, quartz, and porphyry; the granite constitutes the paste in which these are set and agglutinated together. Excellent sections are to be seen in those localities, where the principal rivers, the North and South Esks, the Wast Water, the Isla, and the Ericht, make their passage in debouching upon the plains. In all these defiles the cliffs are precipitous, and often very picturesque, their variegated and bright flesh-colored sides forming a pleasing contrast with the dark waters as they eddy into pools, or dash headlong over their broken ledges. A momentary inspection of this composite rock leaves not the shadow of a doubt upon the mind as to its derivative origin, while its vicinity to the great chain where its several ingredients are to be found as directly points to the quarry whence it was hewn: not, it may be, slowly accumulating, as generally asserted, during the lapse of indefinite periods of time, but rapidly brought together and consolidated, as so many of the sharp angular edges of the materials most unequivocally attest. The finer beds that occur in the vicinity would seem to have been the talus or outgoing of the coarser conglomerate, formed of the minute particles of the same ingredients which had accumulated in the more tranquil hollows of the sea-bottom. The slaty fissile sandstone of Coventry Quarry near Fettercairn (so remarkably tilted up and welded literally to the igneous dyke), stretching throughout the north-east and south-west parts of the counties of Kincardine and Forfar, and prevailing over the districts of Auchtergaven, Crieff, and Callander, may be mistaken in many places for the clay-slate itself slightly altered in texture and appearance.

These conclusions as to the derivative origin of the conglomerate are fully confirmed and borne out by the fact, that the deposit is everywhere found precisely where such materials would be collected, all around the shores of the Scottish Highlands, overlying or fringing the base of the crystalline rocks, filling up the creeks and bays of the primeval world. After thousands of years the massive blocks of syenite, chiseled and half-dressed, are still lying in the quarries of Upper Syria, while the cities for which they were preparing are heaps of ruins in the desert. Nature, left to her own operations, treasures up the waste occasioned by the elements and other forces, and by thus raising outworks and buttresses protects her crystal foundations against the inroads of consuming time.

2. Forming an outer zone or rampart, and overlapping the conglomerate, a gray fossiliferous sandstone constitutes the next member of the Devonian group. This deposit is widely extended, and consists of several beds. One of these is a fine-grained, compact building stone. Another, the well-known flag-stone, is of a more slaty texture, of a dark-blue color, and abounds in mica. These sandstones occupy a great part of the sea-ward barrier by Montrose, Arbroath, and the high grounds of Carmylie. They fold over the Sidlaws on both acclivities of the range, where they form a well defined example of what geologists term the anticlinal and synclinal axes, that is, the rock curves and reduplicates, like a soft flexible substance, according to the undulations of the surface. The several beds cross the Tay in the direction of Dundee, and emerge on the opposite banks at Wormit-bay, Parkhill, and Newburgh; ranging eastward along the northern slope of the Ochils by Norman’s Law and the high table-land of Balmerino.

3. A limestone rock, termed cornstone, from its practical application to grinding purposes in England, occupies a place among the old red sandstone series. This deposit occurs in thin bands of a dull yellowish or blue-colored stone, containing numerous cherty nodules, and, where compact, is of a sub-crystalline texture. The cornstone generally contains more of silicious than of calcareous matter, and is consequently not much prized for building or agricultural purposes. In Scotland no organisms have been as yet detected in it, but in England it yields abundantly remains of the cephalaspis and various crustaceans. This rock is not co-extensive with the other members of the group, nor do we find it continuous in any part of the district which it occupies. It is generally found in small detached patches, as at Glen-Finlay, Meigle, Cargill, on the north of the Sidlaws; at Ballendean, Rait, Meurie, in the Carse of Gowrie; at Parkhill, Newburgh, Clunie, Kinnaird, on the south bank of the Tay; and at Newton and Craigfoodie, on the southern face of the Ochils. At the Newburgh station of the Edinburgh and Northern Railway the cornstone is inclosed among the eruptive rocks, partaking of their common induration, and, except in its distinct lamination, cannot be distinguished in color or texture from the traps.

4. A rock-marl underlies the cornstone in the form of a reddish, variegated sandstone, and contains about fifteen per cent. of lime. Deep sections of this calcareo-arenaceous deposit are displayed along the basin of the Tay, on both sides, from the confluence of the Isla to Stanley, at Pitcairn Green on the Almond, and occupy the ridge from Methven to Crieff. A remarkable vein of serpentine skirts the base of the Grampians in a south-east and north-west direction, of a beautiful dark olive-green, in some places of a blue and whitish color, and at Cortachie Bridge, where it crosses the Esk, containing crystals of diallage. This dyke widens in some parts to nearly ninety feet, of a hard compact texture, and, as the marble of the district on the lakes of Clunie, it is extensively used for ornamental purposes.

5. The geologist, as he pursues his journey by either of the lines of railway that intersect Forfarshire, has still many interesting localities and objects before him. Traversing “the fertile plains of Gowrie” by the Perth and Dundee Junction, he enters at Inchture upon a higher member of the old red sandstone, a fine-grained yellow-spotted bed. The deposit first appears to the eastward of Inchture, in the den of Balruddery, where its outcrop is seen immediately to overlie the gray fossiliferous beds.—The same variety emerges on the opposite bank of the Tay at Birkhill; at Abernethy, where it abuts at nearly right angles against the trap in a small ravine to the south of the village; whence it skirts the base of the Ochils, and occupies the center of Strathearn at Dumbarnie. The Clash-bennie sandstone, doubly interesting from having furnished the first and best specimen of holoptychius, the type of its age, may be regarded as an extension of the Balruddery and Inchture rock. The beds vary a little in their lithological characters, as well as in the deep flesh-color predominant in the latter; still the spherical markings are there, and, as their organic remains are identical, their position in the series may be considered as one and the same. The yellow or upper beds of the old red sandstone fall next to be considered; but these, from their geographical limits, are deferred to the subsequent chapter.

6. Approaching Perth by the Midland Junction, the geologist cannot fail to be arrested by the vast accumulations of sand and gravel, which everywhere present themselves, sometimes in the deep cuttings and railway sections; sometimes in the shape of rounded hillocks or long narrow ridges; and at other places as extended plateaux or sea-margins of different elevations. Along the whole western and southern slopes that overhang the city, these objects give a pleasing variety to the landscape, and form interesting subjects of speculation as to their origin, doubtless the gathered wreck of all the rocks we have been contemplating; for after a careful examination of their contents the conclusion cannot be avoided, that with much of the spoil of the primary rocks, we have here the detrital waste of the entire old red sandstone series. The Carpow cutting, in Strathearn near Newburgh, contains large rounded masses of all the varieties, with their peculiar ichthyolites; the gray, red, and yellow deposit that prevails in Fifeshire, and one solitary patch of which still exists in situ, near the Kirk of Dron, as if on purpose to mark its ancient and more extended boundaries. Nodules and bowlders of the cornstone are likewise abundant. In the vicinity of Perth, the waste of the yellow sandstone is to be found, unmixed in several spots, consisting of thick beds of fine argillaceous sand.

Similar masses of gravelly debris are spread over the middle-basin of the Earn, from Forteviot to Muthil. The Scottish Central cleaves its way for ten miles through scarcely any other material. The dreary monotony of these endless hillocks, around Auchterarder and Blackford, is relieved in part by the fine undulating grassy braes of the Ochils, and the richly-wooded rising grounds skirting the left bank of the river. The geologist’s eye wanders eastward, through the district occupied by the lower basin of the Tay, where the whole was one great estuary or strait, and these the shoals covered by the ancient waters. The eastern shores, from Wormit-bay to Leuchars, are accordingly characterized by vast accumulations of sand and gravel, originating in the same causes and deposited at the same period.

It will excite no surprise, therefore, should we remark that the various beds of old red sandstone now so disjoined, or appearing only as patches, once covered the greater part of the district traced above, extending from the Ochils across the Sidlaws to the Grampians. Nor can there be difficulty in finding an adequate cause for their up-break, especially in the upper members of the group. Consider not merely the constant waste arising from aqueous abrasion and meteroic influences, but also the tearing effects occasioned by the convulsive throes and elevatory movements of the Grampian, Sidlaw, and Ochil ranges, either singly, or, as it may have happened, in combination, when the overlying rocks must have been shattered and broken in every direction, and rendered capable of easy transportation. Although belonging to a posterior geological epoch, these hillocks of gravel and sand are thus the collected records of primeval times, attesting that mighty agencies have been at work in rending the globe, re-adjusting its materials, and preparing them for future combinations.

How speedily, in these first days of creation, does geology make us acquainted with the liability to change and mutation stamped upon all earthly things! The mountains are raised up, and their earliest struggles are to get down again. Nor is it the law of matter, if we may use the expression, to rise. The waters seek the hollows of the earth, because they are material. The rocks, more solid, are subject to the same principle of gravitation, and their course is downward, and their natural place the bottom of the waters. When the rocks were separated from and elevated above the waters, it was not by any virtue or power in themselves to assume these positions. The separation as well as the elevation were the results of direct arrangement; both certainly provided for in the original plan, and yet not the less brought about against their own material tendencies by a special agency. Geology thereby establishes the fact, that the mountains were raised up and the dry land commanded to appear. And now, decomposing and wasting down, we see them seeking back to their old places, to be there re-constructed, and to subserve other purposes.

The Organic Remains, which fall next to be described, are confined to three of the beds, as enumerated above. The first of these, in the order of superposition, is the micaceous flagstone of Carmylie and Arbroath, likewise extending along the south bank of the Tay, and distinguished by the vegetable culmiferous impressions with which it abounds. These, in some places, are so numerous, as to cover the entire surface of the rock. The idea of an ancient marsh is immediately called up in the mind, as one sees stone after stone split up, and all the interstices mottled and streaked over with the stems and leaves of the plants which were fed by its waters. While we write, every pond, and every lake in the neighborhood has crept quietly under its carpeting of ice, a congelation of the living with the dead. How beautiful and distinctly delineated the culms and leaves of the chara locked in its crystal embrace; the flower of the juncus yet lingers on the stalk; and there, how gracefully float the long broad continuous stems of the scirpus lacustris! The pike and perch, both typified in the olden rocks, may be seen motionless as a stone, or softly buoyant as the down, in the clear depths below. Not so brightly, but now as fixedly set, and as minutely preserved, are the fragments of the flora of the Devonian age: if blackened and jetty in their hoary antiquity, these films of mica give light and relief to the darker background of the picture; and shapes, too, were there sporting in the waters,—the seraphim and buckler-headed cephalaspis,—which painter never conceived, nor poet feigned.

These fossils are not in a state of petrifaction, but generally consist in the form of an easily-separated film of carbonaceous matter, or more frequently as a simple coaly marking. Sometimes, but very rarely, the plant is found betwixt the slaty layers, as it were in a dried state, and still perfectly flexible; and the impressions not unfrequently resemble the narrow striated leaves of the alopecurus geniculatus, the floating foxtail-grass, with its knotted culms. There are other specimens, that look like the bark of trees, or the branches of the gnarled oak, ribbed and jointed crosswise. The round dotted patches, varying from the size of a garden pea to an inch in diameter, not unlike, in shape and appearance, the form of a compressed strawberry, are very plentiful. Dr. Fleming, in Cheek’s “Edinburgh Journal” for February, 1831, has figured this organism in connection with the stem, which thereby forms a graceful and well-defined flowering plant, while Sir Charles Lyell considers these berry-shaped forms to be the relics of the ova of some gasteropoda of the period. But at Wormit and Parkhill they are so uniformly, and in such numbers, associated with the culmiferous and leaf impressions, as most strongly to vindicate their claim to a vegetable origin. We have in our collection several specimens, with this organism separated certainly from the culm, but still in such closeness and proportionate size, as, with little aid from the imagination, to infer their former connection, and assign to them a place among the phanerogamous and seed-yielding plants. If so, we cannot too highly prize these relics, regarding them, as they undoubtedly are, among the oldest of organic substances—the first of the green herbs that sprung from the earth—the fragile flower, that withers often in a day, there to attest the mandate of primeval creation. How many seasons have returned; how many seed-times and harvests have covered the fields; what revolutions and changes over all these hills and plains, since that flinty rock formed the soil, and these vegetables sprung from its fertility! They are not admitted among the economic order of the gramineæ; nor whether of marine, semi-marine, or lacustrine origin, have geologists been able to determine.

Of the Animal Remains of fishes belonging to the gray sandstone, the Cephalaspis Lyellii was one of the earliest discovered, as it still constitutes one of the most remarkable of these fossil relics. The head of this creature, and hence the name buckler-headed, is large in proportion to the body, forming nearly one-third of its length. The outline is rounded in the form of a crescent, the lateral horns inclining slightly toward each other, while the anterior or central parts project considerably outward; this peculiarity of structure is occasioned by the intimate anchylosis of all the plates which compose the cranium. The body resembles in appearance an elongated spindle, swelling out on the ridge of the back, and narrowing to the extremity of the tail, which terminates in a long slender point. How like, peradventure, the very dagger with which the murderous Thane of Glammis threatened to render—

“The multitudinous seas incarnadine,

Making the green one red!”

The sanguineous fluid, in those days, was not indeed very plentiful; but the sharp-horned orthoceræ, and the swift predaceous nautili were cotemporaries; and hence, either for protection or attack, we find that, while the head of the Cephalaspis was one entire plate of enameled bone in the upper division, the body was wrapped in a closely woven net-work of bony scales, of peculiar form, and differing from the scales of every other genus of ganoids. The scales along the center of the sides are so high, that their breadth exceeds their length eight or ten times, occupying more than half the height of the animal. Everywhere meshed in smaller but equally impervious nettings, there are of the larger scales, from twenty-six to thirty covering the sides, thereby completing a mail-clad figure of a singularly warlike aspect, and bidding defiance, like his great anti-type, to all his foes,—“let fall thy blade on vulnerable crests”—but now, like Banquo’s ghost, “the bones are marrowless.”

These curious fossils were first detected in the quarries at Glammis, by Sir Charles Lyell, and from their striking resemblance to the cephalic shield of certain trilobites, were supposed, for a time, to belong to the class of crustaceans. The beds of Carmylie and Balruddery, yield these organisms in the greatest abundance. One solitary specimen, a fragment of two inches in length, of the smaller scaly net-mesh, has been obtained by me in the gray rock, on the south bank of the Tay. The heads are uniformly in the best state of preservation; indeed hundreds of these lie entire, where no part of the body has left the trace of an impression. M. Agassiz assigns, as the reason of this, the great difference that exists in the structure of these two parts, and especially in the disproportion of their dimensions and forms, which would offer a distinct resistance to the pressure to which the animals must have been exposed. “If, on the other hand,” he adds, “the heads usually present their superior surface to us, it is because their inferior surface, the cavity of the mouth, the branchial arch and sinuosities of the inferior bones of the cranium, are points of support comparatively more solid, and more adapted for sustaining the matter which has filtered into them, than a larger surface slightly convex, which would naturally be detached from the rock wherever a separation was found in it.”

The Den of Balruddery presents us with a group of very remarkable fossils, comprising, in an area of the gray sandstone of a few square yards, innumerable impressions of the plant-markings already noticed, multitudes of the Cephalaspis, spines, and other ichthyolites, along with two entirely new genera of fishes of the order of Placoids. The sandstone here is of a very slaty character, splitting up into thin layers, betwixt every one of which some organism or other has impressed its form; and the different kinds are often so promiscuously huddled together, as to suggest the idea of some violent commotion in the element which collected and destroyed them. In the “Synoptical Table of British Fossil Fishes,” by M. Agassiz, we find inserted a Parexus recurvus, and a Clematius reticulatus, from this locality; they are represented simply as ichthyodorulites, no complete specimens of the creatures having been presented to him, nor indeed have any been as yet obtained. One of the specimens in the Balruddery collection, when returned by M. Agassiz, was labeled as a Palæocarcinus alatus: and in the 14th Livraison of his “Poisson Fossiles,” he thus writes:—“Enfin j’en dois aussi plusieurs espèces à M. Webster de Balruddery. Parmi ses échantillons j’en ai trouvé plusieurs d’un grand intérêt, parce qu’ils m’ont fait connaître que le genre Pterygotus que j’avais établi, il y a plusieurs années, sur des fragmens très-imparfaits, n’appartient point à la classe de poissons, mais bien en celle des crustaces. Une pareille erreur semble à peine possible, et cependant elle paraît excusable lorsque je ferai connaître les caractères de ce fossile; des botanistes célèbres n’avaient pas hésité à les ranger parmi les Algues. Les Seraphius fossiles des carrières de Forfarshire, que M. Lyell a soumit à la Section de Geologie de l’Association Britannique réunie à Edinbourg en 1834, sont des ces mêmes crustaces gigantesques du terrain Dévonien. Ils offrent des rapports éloignés avec les Entomestracés gigantesques du terrain houiller, décrits sous les noms d’Edotea et d’Eurypterus.” The Lobster, accordingly, of Balruddery is the first discovery of its fossil kind; portions of nearly every organ of the body have been found, so as to make the restoration of the crustacean complete: a creature of at least four feet in length, and as in the fishes of this epoch, the shelly covering is dotted all over with enameled scale-like markings. This magnificent collection remains still undescribed, hundreds of the specimens, from the minute to the gigantic, and of the greatest diversity of character, being only detached fragments of the structures to which they belonged; but enough have we there to testify as to the early prolific abundance of Nature, and that, throughout all ages, her types and forms of life are wonderfully allied.

The interesting locality of Balruddery is succeeded by another in the ascending order of the strata, but lower on the plain of the Carse of Gowrie,—Clashbennie, situated about six miles to the westward. This rock is well entitled to be denominated the Holoptychius Bed, as here the first complete specimen of that remarkable genus was obtained, and of which there are three species in the deposit, namely, H. Giganteus, Noblissimus, and Murchisoni. Three other genera, of the ganoid order of fishes, have left their relics in this bed, some of them in a beautiful state of preservation: these are Glyptosteus reticulatus, Phyllolepis concentricus, and Glyptolepis elegans, all named and described by M. Agassiz.

The Holoptychius ranks among the family of Cœlacanthes, and the term Holoptychius (holos, entire; and ptyche, a wrinkle) is applied to the fossil from the circumstance of the scales being covered with wrinkled dots or markings, the enameled surface of which is indented with deep undulating furrows. Another characteristic feature of this genus consists in the distant position of the ventrical fins, being considerably removed toward the tail, and in the arrangement of the branchial organs, which form two large plates between the branches of the inferior ray, as in the genus Megalichthys. The structure of the “nageoirs,” the rounded form of the ventrical fin, and the manner in which the rays of its anterior edge are insensibly prolonged, in connection with their relative thinness, are also marked distinctions. The head of the Holoptychius is remarkably small in comparison with the size of the body, which, in the Clashbennie specimen measures thirty inches in length by twelve in breadth. The scales are still disproportionately larger than either the head or body, some of them being nearly three inches in length by two and a half in breadth, with a corresponding thickness. The structure of the dermal covering is beautiful in the extreme; it is composed of these scale-plates, articulating, and laced together in such a way as to combine the greatest possible strength with the highest degree of flexibility; and, protected by a rich coating of enamel, it must have been capable of the greatest endurance, and of resisting any pressure. Two thickly set rows of teeth; one inner, and extremely minute, the other large and pointed, completed the equipments of a mouth adapted to seize and crush to powder any intruder upon its pasturage. The vertebral column extended to the extremity of the tail, which was forked or divided into two unequal lobes, a contrivance of nature that enabled the animal to turn quickly on its back before striking its prey. This form of the tail is called the Heterocercal; it is characteristic of most of the fishes of the period, and prevailed during the palæozoic age; when it gave way, at the era of the chalk formation, to what is termed the Homocercal structure, and which still exists in the fishes of the current epoch.

The Phyllolepis is a very striking genus of the same family, and has also been noticed at considerable length by the Swiss naturalist. The scales, or other plates, which covered the body of this fish are of enormous dimensions, being nearly half a foot in diameter, and rounded to an obtuse angle. What distinguishes them from all other scales, and particularly from those of the Holoptychius, with which they have certain external resemblances, is their extreme tenuity, consisting simply of a film of enamel spread over a thin osseous membrane, scarcely so thick as the blade of a knife, and varying from three to five inches in diameter. Their surface is smooth, or slightly marked with concentric wrinkles parallel to the edge of the scale. Two species of this genus have been found, one in the old red, and the other in the coal formation. In the Clashbennie sandstone only a few detached scales have been detected, but sufficiently well preserved to show the superposition, or imbrication, perhaps, in which they stood relatively to each other, the wrinkles serving as grooves by which their adhesion was more firmly effected. One decided characteristic of this organ in the Phyllolepis concentricus is, that it is a little raised toward the middle, whence it again declines or sinks on all sides, after the manner of a roof.

The sandstones flanking the hill of Kinnoul, and stretching along the left bank of the Tay, by Scone and Lethendy, appear to be a continuation of the Clashbennie beds, as also those occupying the ridges by Ruthven and Dupplin, where they assume much of the fissile character and micaceous aspect of the Carmylie flag-stone, but everywhere destitute of organic remains in the whole western district from Perth to Callander. The absence of fossils from particular beds has been accounted for in various ways. But even in the same series of rocks, and where there is no break in the continuity of the strata, it is a maxim of geology that the range of fossils is not always co-extensive with the mineral deposits. Then, as now, the explanation is, that the slightest physical changes affected the tastes and habits of the animal kingdom; the direction and strength of a current; the depth of water; the character and qualities of the sea-bottom; the force of tidal action; the season of the year, being, it is well known, singly sufficient to produce great differences as to the migrations and favorite haunts of almost every aquatic race. And hence it is laid down as a recognized principle in the science, that a particular bed of rock within certain limits is not to be excluded from its place in a system, and another substituted therein, by the mere presence or absence of a certain class of fossils. Individuals, too, will often outlive the family to which they belong, and be found in certain localities intermixed with the races of a higher group of rocks.—And these remarks are applicable to all the formations, less or more, from the lowest fossiliferous strata to the latest of the tertiaries. Applied to the old red sandstone, they serve to explain the fact that, while the precise relative position of the western beds in the district under review cannot in every instance be determined, large spaces or areas are entirely destitute of organic remains which in the eastern, and not distant, localities are detected in the greatest abundance and variety. The system of rocks is unquestionably the same, but neither cephalaspis, parexus, clematius, holoptychius, glyptosteus, phyllolepis, nor glyptolepis, ever would seem to have frequented these parts; whether for the reasons above assigned, or for any other local cause, or simply that they did not like the region—as the grouse and ptarmigan, even now, will not descend to the plains—is one of the recondite problems of animal life connected with the new as well as the older state of things. These beds may yet, however, be discovered to be fossiliferous, as the smallest space in local distance may reveal their hidden stores, to reward the diligent observer, and add to our knowledge of the aboriginal fauna of the district.

The lesson farther taught by the varied phenomena which have passed under review in this chapter would seem to be, that there is nothing fixed or permanent in such arrangements of nature.—These are the beginnings of creation, and both as respects organic and inorganic matter, change and re-construction have prevailed from the earliest periods to which our researches can penetrate.—The Divine Architect did not complete things as we now see them, in one initial act; nor, as we regard quiescence and stability, were the elements and forces of nature so balanced as not to interfere even in violent collision with one another. A world is called into existence. Storms and commotions rend its frame.—Sea and land contend for mastery. And everything within its bounds, like the flux of time, like day and night, summer and winter, life and death, is observed to have emerged into being and form, to have assumed new arrangements, then to have perished; or gradually, as its nature might be, to have consumed away.

No reason can be assigned for all this, as the law or order of events, except the appointment of Him who made and continues the constitution of nature as it is. No adequate cause of creation can ever be conceived but that of the Divine Goodness; and while we never can expect fully to comprehend the wisdom that planned, and the power that carried into effect, the purposes of that wisdom, still the very effort to attain knowledge concerning them, fulfills one great object for which man is made curious about the works of his Maker. In contemplating the wonders of those days, the variety, adaptation and perfection of everything in itself as then constructed, he will always refer to that Infinite Intelligence through whose goodness he is permitted to enjoy knowledge. In becoming wiser he will become better. His increasing knowledge will be made subservient to a more exalted faith in that everlasting “Word” who framed the worlds; and in proportion as the vail becomes thinner through which he sees the origin and course of things, he will admire all the more the brightness of Him who was the true light which lighteth every man that cometh into the world.

Holoptychius Noblissimus.

CHAPTER V.
YELLOW SANDSTONE.

Dura Den, whither the scene of our explorations now shifts, occupies a central position in Fifeshire, and lies equidistant betwixt St. Andrews and Cupar, the county town. This classic field of geology is therefore of the easiest access. The railway traverses the opening to the ravine, a lovely valley of choice archæological as well as fossil remains, where parliaments have assembled and a scepter was contended for, the retreat of learned churchmen, and a refuge in the caverns of its rock for persecuted saints. A day’s excursion to such a place cannot fail to be a profitable as well as agreeable one, where the students of geology, or of botany, or of history, will severally meet with objects suitable to their taste; and, if lovers of the tragic, a short detour to the left will furnish a sight of Magus Muir, of cruel memory and most indefensible policy.

The geological structure of Dura Den is more than ordinarily interesting, presenting, as it does within a limited distance, and in close juxtaposition, the two series of the old red sandstone and carboniferous systems, an included mass of overlying trap, a greenstone dyke, and a vein of galena. The whole length of the dell, with its windings, from the ruins of the castle resting on the conglomerate red, to the outgoing on the south into Ceres basin of the coal formation, does not exceed a mile and a half. The rocks overhang the road which passes through the valley, the sandstone in some places rising precipitously into bold mural cliffs of a hundred feet in height, and presenting colored and well-defined sections of the different layers of which it is composed. These constitute the fish beds of the yellow sandstone group, lying toward the northern extremity of the den, and consist of beds of variegated marls, intermixed with friable arenaceous bands, and hard, compact, fine-grained building stone.

The carboniferous series are separated from those of the yellow sandstone by the greenstone dyke referred to, which immediately, and inconveniently for sight of the junction, interposes betwixt the two systems. The lower beds of the independent coal formation are here thrown up to an angle of 26°, the yellow sandstone adjacent being nearly horizontal, and in no place exceeding an inclination of eight or ten degrees. The coal beds have been lifted up by and repose anticlinally upon the trap, where the cutting for the road has exposed the outcrop of the seams; and thus, in a narrow space and lying on the surface, we may mark the outgoing and the incoming of a vast revolutionary epoch, organic and inorganic, in the earth’s history. The strata, consisting of alternating bands of coal, shale, ironstone, and sandstone, assume toward the head of the valley a nearly horizontal position, abutting against a mass of trap which separates the lower from the upper workable beds of the bituminous mineral in the Ceres basin.

Dura Den, in addition to the interest arising from lithological structure, presents an excellent example of a valley of erosion. The river which traverses it rises at times into considerable volume, and sweeps with violence through the pass; connected above, at one period, with a lake, and acting continuously on soft friable matter, the abrading powers of the instrument are sufficiently adequate to the production of the effect. The qualities of the rocks penetrated may be easily inferred from the windings of the stream—the harder substances occasioning a divergence from the straight course—the soft and marly scooped out into wider and more extended areas. A section of any one of them is thereby labeled for the fullest inspection, which are arranged, not perpendicularly one upon another, but drawn out in longitudinal succession on the floor and sidewalls of the valley, and exhibiting to the geologist, after so many types and forms of the old red sandstone, the first break and most northern limit of the coal metals in the great central basin of Scotland.

The Yellow Sandstone, as it is termed from its prevailing color, though not uniformly so, belongs to the old red or devonian system of rocks, of which the cornstone and conglomerate beds are in the immediate vicinity, and the position and relation of the three to one another easily determinable. The upper or yellow deposit occupies the valley of Stratheden nearly throughout its entire length and breadth, and ranges along the base of the heights of Nydie, Cults, the Lomonds, Binnarty, and the Cleish hills, dipping under the carboniferous lower group, and generally separated by overlying masses of trap. The sandstones, indeed, of both systems, resemble each other so much in color and texture, that in many instances along the line now indicated the trap must be taken as a guide by which to ascertain the qualities and respective positions of the two series. Glenvale, a beautiful ravine which intersects the Lomond range, presents admirable sections of the whole group, in their regular order of superposition and finely displaying their contrasting mineral characters.

Organic Remains. These are abundantly distributed in scales, teeth, spines, coprolites, and other remains, and are to be found in every opening and quarry throughout the range of the deposit. It is only in Dura Den, however, that any entire animal forms have as yet been obtained, and these all confined to a portion of the rock not exceeding thirty yards by three in breadth, a narrow trough excavated for the purpose of forming a water-shed to the mill, which stands in the center of the valley. The fossils derived from this single spot consist of four new genera, and seven or eight new species, that have been added to our catalogue of extinct animals. These remains were all in a state of beautiful preservation; the scales and fins are brightly enameled, and contrasted with the matrix in which they are set, the colors are as vivid and glistening as when the animals were sporting in their native element. The specimens, I believe, of the various collections made in this rich depository by different parties were all submitted to the examination of M. Agassiz, who has figured several of them in his “Monograph” on the old red sandstone, but without completing, it is much to be regretted, his descriptions of the various fossils. We give the following abridgment of such descriptions as are contained in the work.

There are two new species of Holoptychius represented, namely, Andersoni and Flemingii, and these are distinguished entirely by the form and tracery of their respective scales. The H. Andersoni is described as a small spindle-shaped (fusiforme) fish, thick and short, and narrowing rapidly toward the tail.

Holoptychius Andersoni.

The scales are much less than those of the other species, as deep as they are broad, and resembling in general form the scales of the H. Murchisoni found in Clashbennie. What peculiarly distinguishes them is the figure of the ornaments (le dessin des ornemens) of the surface, which are parallel, horizontal, very marked and distant in the A. and never extending in the striæ to the posterior edge. The scales, again, of H. Flemingii are on the sides of the fish deeper than they are broad, and on the belly they become rounder. Their ornaments are also very distinct in the F., consisting of a system of waving lines, which run horizontally toward the outer edge without any perceptible ramification, while the wrinkles of the scale rise from a series of little hills (collines) ranged parallel over the length of the inner edge, undulating and very close. This specimen is represented as very imperfect. The other is nearly entire, the plates of the head and several of the teeth are well preserved, every scale is in its place, and the fins are only wanting to restore the normal outline of the fish. This fossil has been figured and erroneously described in the author’s “Geology of the County of Fife” under the name of gyrolepis (holoptychius now) giganteus, from which, says M. Agassiz, it differs specifically.

From the fossils of this locality has been established the new genus of glyptopomus, the specimen of which being originally mistaken by Agassiz for a platygnathus, but since found by him to differ from that genus in several material points. The scales of the platygnathus, for example, are round and imbricated, possessing in this respect all the characteristics of the scales of the cœlacanthes, while on the other hand those of the glyptopomus resemble the scales of the sauroids, which are rhomboidal or square (ou carrées), closely set and never imbricated, as shown in the subjoined illustration.

Glyptopomus Minor.

Moreover, the platygnathes are lengthy (allongés) in the body, likewise long (longue) in the tail, which is furnished with a very strong fin, whereas the body of the glyptopomes is very thick, and the tail short. The ornaments of the scales of G. bear a close affinity to those generally of the cœlacanthes. Only one species as yet has been found, the glytopomus minor, and figured in the tab. 26 of the “Monograph” under the name of platygnathus minor.

The glyptopomus minor, says M. Agassiz, found in Dura Den, and of which there is but one specimen, is possessed of a body broad and thick, approaching in form to that of the holoptychius. The fish is lying on the belly, and turned slightly to the left, so that it is the back and right side which are represented in the plate. The head is proportionally small, covered with bones very irregularly carved, presenting a dense and diversified granular aspect. On the side of the head there is a large enameled plate, which shows that the cheek was covered, as in the polypterus, with one single osseous plate, on the under edge of which was fixed the large masticatory muscle. The scales on the body of the fish are large, high on the sides, and nearly square on the back, where in the middle they form an oblique series converging to an acute angle. The scales are very thick set on the side of each other, and apparently connected only by means of the skin to which they are attached. The enameled surface is not smooth, but rather marked with a fine granulation, which imparts a rich velvet gloss to the scale. Traces only of the fins are preserved, partly of the ventral, partly of the dorsal or caudal, and the rays of which are all apparently short and slender. This specimen forms a part of the author’s collection, but inadvertently described as belonging to that of Professor Jameson.

Another genus, established from the fossils of Dura Den by M. Agassiz, is the Pamphractus, of which there are two species, Hydrophilus and Andersoni. These are both in the collection of the author, and have a special history of their own, from which, when read in all its details, it would appear they have suffered as roughly at the hands of geologists in simply determining their class, order, or genus, as they ever did from the physical revolutions amidst which their lot was originally cast.

Before the type of a new and strange form called Pterichthys, had been determined by this learned palæontologist, collectors were everywhere puzzled by the specimens of the animal that, from time to time were casting up. The winged appendages of the sides of the head, as movable fins, had easily given rise to a variety of opinions concerning their true affinities, and which, says M. Agassiz, “have been regarded by the most able naturalists successively as Tortoises, Fishes, Crustacea, and even Coleoptera.” The fossils of Dura Den were at first regarded by him as belonging to the type as well as genus Pterichthys, and my specimens were actually returned from Neufchâtel so named—the “broad” and “narrow” species—and the label still remains attached. Meanwhile, five or six species of the genus Pterichthys had been already determined and described by him, from the fossils of Cromarty and Morayshire—these in the collection chiefly of Mr. Hugh Miller; and Mr. Miller being, about the same period, engaged in the preparation of his work, “The Old Red Sandstone,” speedily under the new nomenclature, as he was so opportunely furnished with the materials, gave the public the benefit of M. Agassiz’s discovery and version of their true and authentic history. What we had hastily, certainly, but still influenced much in the matter by the judgment of others, referred to the order of Coleoptera, he was enabled at once, upon the inspection of a Dura Den specimen, and from its very striking resemblance to his own, to pronounce to be a Pterichthys. A few pages before he had stated that he could make nothing of the creature, although some specimens of the fossil had been in his possession for a period of nearly ten years; but now, he was able to record,—“I very lately enjoyed the pleasure of examining the bona fide ichthyolite itself,—one of the specimens of Dura Den, and apparently one of the more entire, in the collection of Professor Fleming. Its character as a Pterichthys I found very obvious.” But short-lived, indeed, are all mundane enjoyments. The most intellectual, in the revolutions of science, are not exempt from their general character of vanity. While the two northern sages were thus gazing, in all the raptures of a new discovery, “upon the bona fide ichthyolite itself,” the philosopher, under the shelter of the Jura, was doubting, re-examining, and finally correcting, his own first judgment; and, while the virgin pages of “The Old Red Sandstone” had scarcely time to reach their author, the “Monograph” was announcing to the world the determination of a new genus, and that the fossil of Dura Den was a Pamphractus, and no Pterichthys at all.

“I had at first,” says Agassiz, “connected with pterichthys the only species known of that genus, by calling it pterichthys hydrophilus, but a more profound study and attentive comparison of that species with the genus coccosteus, have proved that it ought to form a distinct genus, intermediate betwixt pterichthys and coccosteus, which I have named pamphractus, in consequence of the divided form of the carapace. The pectoral fins of pamphractus resemble very much those of the pterichthys in their form, being slender, elongated, and crooked (courbée). But the plates of the carapace are all differently arranged. The central plate is very large (énorme); it covers two-thirds of the whole carapace, and unites the anterior articulation of the head with the carapace. The lateral plates, which acquire so great a development in the pterichthys, are here reduced to narrow stripes, stretching to the edge of the carapace; while, on the other hand; the posterior plates are of very great size, and form with a small intercalated plate the extremity of the carapace. The disposition of the plates of the head is likewise very different from that of the pterichthys, in which we discern no thoracic cincture as in that genus, but a transverse line, which separates in a striking manner the plates of the head from those of the carapace. We see not any portion of the tail; but I presume that it would bear a resemblance to the form of that of pterichthys.” Agassiz thus concludes his description of pamphractus, which we have partly abridged:—“The excessive development of the central plate of the carapace which reaches the articulation of the head—the absence of a thoracic cincture making the round of the body—and the distinct separation of the occipital articulation, will always distinguish this genus from that of pterichthys.”

Again, however, the ashes of the dead have been disturbed, the history has been recast, and the old genealogy attempted to be restored. Sir P. G. Egerton, in a paper read before the Geological Society of London, on the 19th April, 1848, and a copy of which he did me the honor to transmit, has examined very minutely every organ and portion of the animal as delineated in the “Monograph,” and is satisfied that it is, indeed, still to be regarded as a genuine pterichthys. However, Sir Philip very cautiously adds,—“Having never seen a specimen of pamphractus, I should not be justified in expressing any positive opinion respecting this genus, but I cannot help thinking that it is founded on a specimen, showing the true dorsal arrangement of the lorication of the Pterichthys.” Accordingly, Mr. Miller, who supplies a considerable portion of the paper in question, affirms, with abundant confidence, that he has been able to penetrate the mystery of the error. “I have succeeded,” he says, “in tracing to its origin the Pamphractus of Agassiz. The specimens which he figures could never have furnished the materials of his restoration—These materials he evidently derived from the print of a Pterichthys of the upper Old Red (showing the dorsal superficies of the creature), given by the Rev. Dr. Anderson of Newburgh, in his Essay on the Geology of Fifeshire (‘Quarterly Journal of Agriculture,’ Vol. XI, 1840), as that of a fossil beetle.” Now, with all submission, this hypothesis is wide of the fact. While Mr. Miller was inspecting, at Aberdeen, “the bona fide ichthyolite itself,” and which, as we shall immediately see, was not a Pterichthys, Agassiz had both the print and the real specimens lying before him. The impressions on the slab are eleven in number, three of the “broad” and eight of the “narrow” species; and, comparing the one with the other, the print with the fossil, he records, “They have been figured very fairly by Mr. Anderson, in his interesting Memoir on the Geology of Fifeshire.” “But,” adds Mr. Miller, “I have ascertained, by the examination of the greater number of specimens of this species yet found, in the general outline of the carapace, which was longer in proportion to its breadth than in the print, and not defined by such regular curves.” ... The print is a perfect transcript of the fossil, as if taken in a mold,—curves, projections, and tubercles all duly and “fairly” preserved, as in the original; and, with all the materials, and so many actual impressions before him, Agassiz hesitated not to change his views, and to feel assured that it was really a Pamphractus, not a Pterichthys, that he was examining. Farther, we have only to add, that in the Essay in the Quarterly Journal of Agriculture, it is not true that the print of a Pterichthys is there “given as that of a fossil beetle;” the higher patronymic had, ere the publication of the prize essay, been withdrawn; and the author, along with all others, states, he was waiting the judgment of the highest and most competent authority from the blue lake of Neufchâtel.

And thither also, it would now appear, that other inquiries had been transmitted respecting the organisms of Dura Den, to be famed by modern, as it had already been by ancient, genealogical claims. We suspect, at least, it is of “the bona fide ichthyolite itself” that M. Agassiz, in the “Monograph,” speaks in the following extract:—“Dr. Fleming m’a communiqué le dessin d’une pétrifaction recueillie par lui à Dura Den, qui resemble beaucoup, quant à la forme du Pamphractus hydrophilus. La tête est courte, arrondie, large, presque en forme de croissant, le corps est allongé, formant avec la tête un ovale qui se termine en pointe en arrière. Les pectorales sont grêles, courbées et aussi longues que le corps. L’articulation de la tête avec le corps est très-nettement marquée, d’une manière qu’a la forme de la carapace près, qui est beaucoup plus pointue, on croirait voir un Pamphractus. Mais ce qui distingue surtout ce fossile (à en juger du moins d’après le dessin qui n’est, à vrai dire, qu’une esquisse) c’est qu’il n’y a pas de plaques separées, et que toute la surface de sa carapace ne montre qu’une granulation uniforme et continue, si toutefois la délinéation des plaques n’a pas été omise par le dessinateur. Nous aurions donc dans ce fossile un genre nouveau de cephalaspide, caractérisé par la forme de sa tête et par sa carapace uniforme. Quoi qu’il en soit, j’attends de plus amples informations sur ce sujet, avant de préciser davantage les caractères de ce type, et je me borne à reproduire les contours de ce dessin, Tab. 31, fig. 6, afin de fixer d’une manière plus particulière l’attention sur ce fossile.”

Now, making every allowance for the imperfection of the sketch of Dr. Fleming, (qu’une esquisse), and which had not the aggravation of being a “print,” only see how many marvels have been successively evolved out of “the bona fide ichthyolite itself:”—it is not a Pamphractus, though very much resembling it in form—it is not a Pterichthys, of which alliance there is not a hint even dropped by Agassiz, though its character as a Pterichthys Mr. Miller “found very obvious;” but “we have in that fossil a new kind (genre) of cephalaspis, characterized by the form of its head, and by its uniform carapace,” all which characters have been overlooked in “the pleasure of examining the bona fide ichthyolite itself—one of the specimens of Dura Den, and apparently one of the more entire.” Has this creature undergone a still further metamorphosis, numerous as those of the Pterichthys itself? Or what specimen is it which now rejoices in the appellation of Homothorax Flemingii, also again challenged or suspected at least by Sir P. Egerton, not to be its true designation! But, quocunque nomine gaudeat, the cabinet of science is enriched by the addition of a new and remarkable fossil fish.

Repeatedly, since the notice in Mr. Miller’s work of the Dura Den fossil, and his fanciful commentary on the truth and accuracy of the plate in the “Geology of Fifeshire,” have I examined, compared, and recompared the design and the original, and never have I been able to detect the slightest disagreement, even in the minutest feature. Others, and parties innumerable have examined them freely in my presence, have pronounced as to the fairness of the representation. There are five figures in all upon the plate of the Dura Den fossils; they were all, fossils and figures, under the ocular inspection of M. Agassiz; one of these, Holoptychius Andersoni, he has figured in the “Monograph;” the representations are identical, and all are declared to be “figured very fairly.” True, the pamphractus had not been able to preserve the tail, nor any trace even of that member. Agassiz did not think himself justified in supplying the deficiency. I added none either, “carefully sinking” the nonentity. But Mr. Miller had a point to establish: the fossil must be one and the same with the bona fide ichthyolite itself, which appears to have retained the caudal appendage. It will not certainly account for the obliteration of this organ in all the specimens of Dura Den, that, in common with Pterichthys and Coccosteus, the Pamphractus was not possessed of the heterocercal structure, so characteristic of the fishes of the period. But yet it is not there. Then, “the tubercles seen in profile,” are exaggerated: Agassiz thought fit, upon examination, to retain the exaggeration, as Nature, he perceived, had designed. And now, Mr. Miller finds it proper to communicate to Sir P. Egerton, that after examining the specimens (presented by me) in the Museum of the Highland and Agricultural Society in Edinburgh, “one of the most striking specific distinctions of the creature consists in the length and bulk of the arms, and the comparatively great prominence of those angular projections by which they are studded on the edges—projections which seem to be but exaggerations of those confluent lines of tubercles by which the arms of all the other species are fringed.” So, Nature has her “exaggerations,” likewise! and the first of the genus which ever rose to the stroke of the hammer, has in no degree been misrepresented in its fair proportions, except that the angular projections referred to are not so prominently developed as in other specimens in the author’s collection.

It will readily be inferred from all this that the locality of Dura Den is entitled to much consideration in consequence of the variety of its interesting remains, not to speak of the diversity of views which the remains themselves have occasioned in so many quarters. The Pterichthys, Pamphractus, Homothorax, and Cephalaspis are all of the family Lépidöides, and have such a close affinity in outward form as readily, in mutilated specimens at least, to be mistaken for each other. The appendages of the head, having the appearance of wings, suggested the term pterichthys, the winged fish: the plates covering the body, according to their number and form, gave rise to the generic distinctions; and the species of each have subsequently been determined by minor differences. The external organs in all were enameled, and discover, like the fish of the period, the tuberculated surface. The Pterichthys of the more northern counties vary in size from nearly a foot to an inch in length, and generally the wings of these, so far as they have been figured in works, are extended horizontally and perpendicularly to the body. The Pamphractus of Dura Den are all nearly of a size—about two inches and a half in length,—the wings in every instance depressed and inclined to the sides, and in no instance of the twenty to thirty specimens exhumed from the rock, has the tail been appended, or a fragment of the caudal organ detected. The cephalaspis has only been found in the lower beds of the system, and highly important would be its discovery in the upper, where, however, we have reason to think the new genus Homothorax has been substituted in its place. Mrs. Dalgliesh of Dura, in whose collection we found a Glyptopomus, and a slab containing several impressions of the Pamphractus, has kindly, and with a commendable love of science, informed us that her quarries are freely open for the researches and explorations of geologists, and that every facility will be afforded them in their interesting task.

In addition to the fossils already referred to, I find in the specimens of my collection returned from Neufchâtel, that two are labeled as Diplopterus, new species; two as Glypticus, new species; and one as Holoptychius, new species. This last is now figured in the “Monograph” as the Platygnathus Jamesoni. None of these are described in the narrative of the work, so that until his return from America, where palæontology will unquestionably reap much from his indomitable perseverance, his almost instinctive skill, and vast learning, we cannot expect that M. Agassiz will have leisure either to supplement the deficiencies of his great work, or confirm his former conclusions against the alterations suggested in his absence—suggested certainly in no small degree upon fanciful organization and mistaken assumption.

Platygnathus Jamesoni.

In closing our review of the old red sandstone, we shall briefly state the principles of classification of fossil fishes, as determined by M. Agassiz, from which it will be seen by the earliest types of the marine vertebrata, while admirably suited to the perturbed condition of the element in which the strata were formed, differ widely in their structure from all existing races.

The fishes of the present era, it is well known, are divided into two great classes, the cartilaginous and the osseous. In the former are comprehended the sharks, rays, and sturgeons of our present seas; the latter embrace the salmon, cod, herring, and the various kinds possessed of similar forms. The bony structure in all the cartilaginous class is soft, destitute of fibers, and contains scarcely a trace of earthy or calcareous matter. The osseous fishes, on the other hand, are constructed internally of true bone, composed of calcareous matter, like that of birds and quadrupeds, which is possessed of a fibrous arrangement, of great hardness and capable of long endurance. Now, it would appear that the fishes of the old red sandstone belong almost exclusively to the cartilaginous class. The internal frame was composed chiefly of this soft, soluble substance; hence it is that no portion of the inner body of the fish, in any of the fossil specimens, remains.—The teeth and scales, with fragments of the bones of the head, are all that have survived, but so hard and enduring has been the scaly outer coating, that the figure and contour of the animal have been preserved entire. The specimen of Holoptychius Andersoni, from Dura Den, is still enveloped in its original covering, not a scale in the whole body displaced or missing, the head and belly slightly compressed, while the posterior ridge of the back and tail is sharp and angular.

Here, then, in this class of animal life, we find that what is defective in the internal structure—if it be a defect—is completely supplied in the outer appendages, whereby the fishes which have the softest bodies are possessed of hard, horny skins, coated with enamel. Their bones are thus all on the surface, sometimes in the form of scales; sometimes assuming the shape of spines and tubercles; now in small, now in large plates; and often disposed in the most singular and grotesque arrangements, as in the genus coccosteus, or the osteolepis, whose entire skull consisted of shining naked bone, and in the cheiracanthus, a creature possessed of fins scaled and enameled all over.

The Swiss naturalist, accordingly, in adopting a new principle of classification, so essential in the case of the fossils of the old red sandstone, has made the scales and external organs the groundwork of his system. The classification of Cuvier and the older naturalists proceeds mainly upon the character and disposition of the fins. Hence the order of the Acanthopterygii, or thorny-finned; and the Malacopterygii, or the soft finned order.—The classification of M. Agassiz, proceeding upon the characters of the scales and plates, has given rise to the following orders, namely, the Placoid, or broad-plated scale; the Ganoid, or the shining-scale; the Ctenoid, or comb-shaped scale; and the Cycloid, or marginated scale. Upon the simple basis of these four orders, he has constructed his system and composed his “Poissons Fossiles,” the standard authority in fossil ichthyology, and elaborate monument of his learning and genius.

The relations, as well as distinguishing peculiarities, of the fishes of the old red, are thus described by Agassiz:—“Of the Placoidian order,” he says, “the genera ctenacanthus, onchus, ctenoptychius, and ptychacanthus, are provided with spinous rays to the dorsal fins, resembling the gigantic ichthyodorulites of the carboniferous and jurassic formations, but differing in their less considerable size; they are distinguished among themselves by the forms and ornaments of their rays. In the order of ganoid fishes, the genera acanthodes, diplacanthus, cheiracanthus, and cheirolepis present themselves at first sight as a separate group; for although covered, like the others, with enameled scales, these are so small, that they impart to the skin the appearance of shagreen. The manner in which the fins are sustained by spinous rays, or the absence of these rays, and the position of the fins themselves, have served as characters in the establishing of these genera. The genera pterichthys, coccosteus, and cephalaspis, form a second group exceedingly curious: the considerable development of the head, its size, large plates which cover it, and which likewise extend over the greater portion of the trunk, and the movable appendages in the form of a wing, placed on the side of the head, give to them the most remarkable appearance. It is these peculiarities, indeed, which caused the class to which these genera belong for a long time to be misunderstood. The large bony and granulated plates of coccosteus, led to their being considered as belonging to trionyx: and it will be sufficient excuse for this error to call to recollection, that the greatest anatomist of our age had sanctioned this approximation. The form of the disc of the head of the cephalaspides, which has the appearance of a large crescent, and their more numerous, but very elevated scales, resembling the transverse articulations of the body, explain how it was possible to see in these fishes the trilobites of a particular genus. Lastly, the winged appendages of the sides of the head of pterichthys, as movable as fins, have easily given rise to the variety of opinions concerning the true affinity of these singular creatures, and has caused them to be taken at one time for gigantic coleoptera, at another for crustacea, or small marine tortoises; so little do the types of the classes appear fixed in certain respects at these remote times. Another singularity of these genera is the association to the bony plates of the head of a vertebral appendage, which is far from having acquired the same solidity; but appears, on the contrary, to have remained fibro-cartilaginous during the whole life of the animal—resembling in this respect the skeleton of the sturgeon.

“It would be difficult to find among recent fishes, types presenting any direct analogy with the genera pterichthys, coccosteus, and cephalaspis; it is only from afar that they can be compared to some abnormal genera of our epoch.... The analogy which they offer, on the one hand, in form with the dorsal cord of the embryo of fishes, together with the inferior position of their mouth, which is equally met with in the embryos; and on the other hand, the distant resemblance of these fishes to certain types of reptiles, present the most curious assemblage of characters that can possibly be conceived. A third group of fishes belonging to this formation, comprises those genera whose vertical fins are double on the back and under the tail, and which approach very near to the caudal. These are the genera dipterus, osteolepis, diplopterus, and glyptolepis, which differ from one another by the form of their scales and their dentition. And lastly, it seems necessary to regard as a fourth group of this order, the genera which are characterized by large conical teeth, situated on the margin of the jaws, between which are alternately smaller, and indeed very small ones, in the form of a brush. Such are the genera holoptychius and platygnathus, and the genus recently established by Mr. Owen under the name of dendrodus, and respecting which this learned anatomist has given some exceedingly interesting microscopical details.”

The philosopher here, in these views as to the primitive diversity of the ichthyoid types in the old red sandstone, adduces such illustrations and others not quoted, as subversive of the theory of the successive transformation of species, and of the descent of organized beings now living, from a small number of primitive forms. He asserts the doctrine that the characteristic fossils of each well-marked geological epoch are the representatives of so many distinct creations, and affirms that he has demonstrated by a vast number of species that the presumed identifications are exaggerated approximations of species, resembling one another, but nevertheless specifically distinct. M. Agassiz introduces the same doctrine in his latest great work, the “Iconographie,” wherein he goes the length of saying, that, even when species are, so far as the eye can judge, identical, they may not be so—that there may exist species so nearly allied, as to render it impossible to distinguish them—and reiterates that each geological epoch is characterized by a distinct system of created beings (the results of a new intervention of creative power), including not only different species from those of the preceding system, but also new types. Under his safe guidance we have glanced at the earliest groups and forms of life upon the globe, and have seen the simple structures of the beginning succeeded by higher, if not more perfect or more complex, at least by creatures capable of a wider range of action and enjoyment. The deductions and sweeping inferences of geologists may be often vague and uncertain; but a science, whose direct aim is to decipher the records of the past and compare the successive types of animal life upon the earth, deals with important objects, and leads to salutary trains of thought, keeping continually before the view the Fountain-Head of all being; and adding a new proof to the sublime doctrine, that Man who is privileged so to range through creation and time will himself outlive a term of existence, measurable by a few points of space and a few moments of eternity.

Pamphractus Andersoni.

CHAPTER VI.
TRAP ROCKS.

We do not select the rocks which form the title of this chapter from mere arbitrary choice, or because they are geographically connected with the district under review, but because they are immediately the next in the chronological order of our course. The Sidlaws and Ochils have their position as precisely determined in relation to time as to space, for difficult often as it may be to fix the sequence of events within the historical era, there is generally no lack of evidence by which to ascertain, in the far remoter times, when the several strata and the igneous masses assumed their respective places on the surface of the globe. The proofs here are of a cumulative character, and irresistibly conclusive. The animate and inanimate things of earth, the living and the dead, are both admissible witnesses in the question, and their testimony is alike unexceptionable. The saurian seas had been disturbed upon the upheaval of their beds; these with their organic contents were elevated by the irruption of plutonic matter, and in their altered position gave a bolder contour and additional bulk to the primitive land. New accumulations were forming during the devonian period in the waters still mightily agitated along the lines of disturbance; new races of scale-enameled creatures occupied their depths, and huge crustaceans anchored among their rocky shallows. The interior regions again let loose their giant forces, and these chains of hills rose above the surface, disrupting and heaving into day the various deposits of the old red sandstone. Hence the formation of the one set of rocks preceded, in the order of time, the elevation of the other: not an islet appeared over all these parts while the sedimentary strata were accumulating beneath: plants and trees covered the flanks of the Grampians, algæ and fuci abounded in the waters, and myriads of fishes sported amid their luxuriance; but as yet there was no basin of the Tay, no fertile Carse of Gowrie, no kingdom of Fife stored to repletion with its precious metals of iron, lime, and coal. The Sidlaws and Ochils, therefore, become invested with even a romantic interest, when we thus view them in their geological relations—their age precisely defined—and themselves, flinty and weather-stained, the memorials of the vast convulsions and changes of nature. They mark the outgoing of a period comparatively barren of vegetable life, and the incoming of the exuberant products of the carboniferous epoch.

I. The structure of the Sidlaw and Ochil ranges, from the amorphous character of the rocks, furnishes little or no room for geological description. These nearly parallel chains of hills, separated only by an interval of from two to five miles, and forming the lower water-shed of the basin of the Tay, consist of the various members of the trap family usually denominated whinstone, and whose structure is very different, upon a glance, from that of the sandstones and other sedimentary deposits we have been considering. This class of rocks have all a tendency, in mineralogical phraseology, to a spathose structure, and discover at least the rudiments of crystallization: there is no lamination in their internal texture, and the lines of stratification which they sometimes exhibit are assumed, or impressed by the previously consolidated strata among which they have been injected. They are not lavas, which are sub-aërial products, nor are they aqueous formations, whose materials have been deposited in water. These rocks are the results of igneous fusion deep under the crust of the earth, poured over the bottom of the sea, and protruded into the diversified dome-shaped forms which they generally present.

Trap-rock consists of several varieties, as porphyry, clinkstone, compact feldspar, amygdaloid, greenstone, and basalt. These all pass into each other by insensible gradations, often forming one continuous mass, for the most part composed of the same ingredients, and have in consequence been regarded by geologists as belonging to one group, produced under similar circumstances, and elevated at intervals about the same period. The porphyritic structure prevails generally in both chains, and “porphyry has the peculiarity of being rarely found in any but the primary strata: it seems to be the whinstone of the Old World, or at least that which is of highest antiquity in the present.”[2] But not only are both ranges characterized by the same qualities and texture of rocks in hand-specimens, one hill answering to another; they also preserve the same general features of outline, and the same relations to the disrupted sandstones among which they have been injected. The highest point, for instance, in the eastern division of the Ochils, is Norman’s Law, attaining an elevation of nearly one thousand feet above the level of the sea: in its uprise the mass has brought along with it the lower beds of the gray sandstone, which flank its northern and eastern sides, within three hundred feet of the summit. To the north and west of Dundee the highest points of the Sidlaws are encompassed in like manner with their analogous beds of the gray rock. And so in every locality, whether along their base lines, or among the numerous ravines and valleys that intersect their cultivated slopes, the strata may be seen cropping out, bearing testimony to the convulsive movements to which they have been exposed, and the altered positions they have in consequence assumed.

A remarkable bed of conglomerate or tufaceous trap intersects the chains at different, but generally corresponding, points of elevation, varying from two to four hundred feet above the sea-level. On the Ochil side this bed crosses the chain of hills from Letham school-house to Lindores Loch, where, along the line of the Edinburgh and Northern Railway, the out-crop may be observed at various places—very interestingly on the western slope of Clatchart—and again appearing at intervals toward Abernethy, whence it is traceable through the glen. In the ravines of the Sidlaws, behind Rossie Priory, in the den of Pitroddy, on the face of Kinnoul and Moncrieffe Hills, and across the ridge intersected by the Perth tunnel, indications of the same tufaceous bed can be traced, consisting, for the most part, of quartz rock, schist, and rounded masses of the different varieties of the trap, mixed not unfrequently with bowlders and smaller pieces of the gray and red sandstones. This formation has, doubtless, been produced on the bottom of a troubled sea, where the crust has been exposed to violent action—much of it comminuted and broken into fragments, rolled and fashioned into nodules, large portions of it torn up, but retaining their continuity for a space—when the molten flood has poured from below, and diffusing itself through the mass, the whole, after successive eruptions, has been lifted to its present elevation.

II. The amygdaloidal portion of these hills forms an interesting feature, and prevails very widely in both chains. This rock has a conglomerated stratified appearance in some places; but generally the matrix is very compact, rather porphyritic, of a dark brown or greenish hue, and when exposed to weathering, the innumerable small cavities or vesicular tissue by which it is laminated are prominently exposed. These cavities are filled with zeolites, carbonate of lime, chalcedony, prebnite, and various other crystalline silicious deposits. The green hue is derived from the decomposition, on the exposed surfaces, of the imbedded substances. This rock forms the true habitat of the richest and most beautiful specimens of the agate and jasper family, of the purest Scottish pebble, and of large sparkling geodes of amethystine crystals. The agates of Kinnoul and Moncrieffe are prized by lapidaries, as they are admired by amateurs, and no mineralogist should fail to visit the romantic pass of Glen Farg—illustrated by the classic pens of Galt, Lauder, and Scott—adorned and stored, in every niche of its serpentine course, with calc-spars, analcime, chabasie, stilbite, heulandite, konilite, and the entire family of the zeolites, presenting often fasciculi of crystals several inches in length, thin as silken threads, and rivaling frost-work in the transparency and brilliancy of their texture. The mass of rock constituting Bein Hill, and intersected by the turnpike for miles, appears as a simple agglutination of nodules of the size and color of garden peas, and consisting principally of analcime, zeolite, and chalcedonic pebbles.

What account is given of these curious formations—of their color, structure, and qualities—all so different from those of the surrounding matrix? Assuming the igneous origin of the trap family of rocks, and against which there can scarcely exist the possibility of an argument, it is supposed that, when in the act of cooling, cavities would necessarily be produced in the heated molten mass by the expansive power of gases, and that upon their escape silicious and other deposits would be formed in the empty spaces. All the ingredients of the included crystals, of every genus, are plentifully diffused through nature, mixed up with the matter of every kind of rock; air and water are nowhere wanting, and substances sufficiently porous, for their transmission; a lamination or separation of coating, layer upon layer, is discernible in every agate; while the still partially existing hollows in some nodules, and the concentric nature of the bands of earthy matter which lines their surface, clearly demonstrate the deposition of the outer prior to that of the inner layer, and prove that at the very time when the crystallization had commenced, the cavities had assumed the form and shape which they now retain. Sometimes, too, the nodules have a compressed or flattened appearance; and the explanation in such cases is, that the cavities, if formed during the cooling of the beds, must have been altered in their shape by pressure either before the deposition of the silicious matter, or during the successive formation of the layers. Other, and indeed many, theories are broached, among which the most plausible is, that the cavities in which the agates are now found were caused by the “molecular aggregation of the silicious particles compelling the surrounding matter to yield in proportion to the attraction of these homogeneous particles.” The former explanation, however, is the most generally adopted, the most obvious in its conditions, and the most accordant with the existing processes of nature, the laws of heat, and the order of crystallization. The porosity and fibrous structure of agates, consisting of a congeries of minute radiating fibers at right angles to the rings or concentric layers, have also been established from microscopical examination, and hence the diversity of their colors, whether from vegetable matter or metallic oxides everywhere so abundant in the soils and crust of the globe.

The same law or mode of formation applies to crystallized minerals generally, and has continued to operate from primitive times to our own in their production. The sparkling topazes of Cairngorm and gigantic crystals of the Alps—the semi-opal of Iceland and the heliotrope of Kinnoul—the dazzling emeralds of Brazil and Ethiopia—the stupendous garnets of Fahlun—the delicately-colored fluors and calc-spars of Derbyshire and Cumberland—the gorgeous rubies and sapphires of India and Ceylon—the beautiful prismatic idocrase of Vesuvius and Etna—the splendid amethystine geodes of Oberstein, Siberia, and Spain, little grottoes lined with polished geometrical figures, all declare a common birth as they all nestle in rocks of a common origin. The diamond, the richest as it is the rarest of all, belongs to a totally different class of crystallized bodies, and owes its formation to the agency of entirely different causes.

III. The dykes or veins form another striking feature among the geological phenomena of these hills, and seem as if nature intended them for lacings or bands to give greater cohesion and stability to its parts. They consist of long narrow strips of rock, which have made their way through the previously consolidated strata, intersecting the planes of their several beds at nearly right angles, and constituting among themselves a system of parallel and vertical partitions in the rock. Once observed in any district, these dykes are of too marked a character not to excite inquiries as to their uses and mode of formation; and occurring, as they do, in every region and among all classes, from the oldest primary to the newest tertiary deposits, they are obviously designed for some great purpose in the plan of Creation.

Veins may be described as tabular masses that penetrate the earth’s crust to an unknown depth, and almost invariably consist of different materials from the rocks they traverse. They are supposed to have all been in a state of fusion, and either themselves to have produced rents and fissures in their pressure upward, or to have filled with their molten ingredients such as from other causes were already existing. When detected in sandstone or other stratified formations, they are readily distinguished, and acknowledged to be of foreign origin as well as of posterior date. The matter of them consists generally, among the secondary formations, of basalt or greenstone; more frequently of porphyry and feldspar among the older and crystalline rocks. In their passage through whinstone the sides of the veins are usually smoothed and polished as if by the action of another body rubbing against them; the sandstones and other sedimentary rocks are indurated, or discoloration may be traced for a considerable space inward from the walls of the vein. There is no mixing up of the materials of the dyke, nor any approach to incorporation with those of the including mass. After exposure on the surface to atmospheric influences, the basalt or greenstone splits up into large tabular blocks, which become extremely friable, and scale off in thin layers, leaving a central ball, which exfoliates in like manner, and gradually molders into dust. These dykes are very numerous in the Grampians, occurring everywhere, and diverging in every direction through the primary rocks. They traverse the lower district on the south of the range, five or six crossing the Tay, and running nearly parallel in a north-westerly course. They rise above the sandstone in various places of Strathearn, forming mural ridges, furrowed into broad jointed masses, or piled loosely above each other. The outgoing of some of these remarkable concretions can be traced into the German ocean. From St. Andrews westward, their line of bearing may be detected, both among the trap-hills and the sandstones which flank them, and like well-run stags, after debouching from the Ochills and Sidlaws, converging upon the forest of Glenartney. Doubling, winding, and dragging out and in among the passes from Crieff to Comrie, two of them may be descried on the steep face of Aberuchill, fairly scaling its lofty summits; and driving onward, may others be observed on the south of the Ruchle, to the far heights of Uam-Var.

The etymology of the term Ochil, would seem to be connected in some way with these geological phenomena. A tradition exists that, from time immemorial, the earthquakes of Comrie were cotemporaneous with subterranean movements or noises in the Ochil range, near Devon. The Gælic word ochain, or ochail, signifies, according to Armstrong, “moaning, wailing, howling;” and hence it is inferred that the name of the “Moaning Hills” may have been given to the range, from the sounds so frequently heard in the district. There can be no question as to the probability of a subterranean sympathy betwixt the two localities, through the instrumentality of these dykes, or otherwise; and, though the series of events referred to above belong to an anterior age—far remote, indeed, from the human and all its traditions—a plausible origin is thus given to the name, in connection with an analogous series of events that did happen within the human period.

IV. A vast historical interest, therefore, is to be attached to these hills, and their phenomena of veins, connected as they are with the first elevatory movements of the globe, and when form and outline were being given to its massive fullness. The hand of the Creator is clearly seen in raising them up from the depths below. Not a particle of the entire volume is in its original position, or that which it would of itself statically assume. God formed everything for use, while beauty and agreeableness of shape are inseparably combined. When viewed in the light of causation, it is not enough merely to say, and there to stop short, that we see in the outward face of nature the impress of power, wisdom, and goodness—that none of these things made themselves—that the rocks and mountains are an image of Jehovah’s greatness—the streams, plains, trees, corns, animals, the effect of His love and care. All this they unquestionably are, but they are more. Their arrangement and disposition, beside their mere existence, evince a continued superintendence—a purpose and a will to maintain an order and construction of elements which would otherwise separate and dissolve—a keeping together, and as one, each after their own kind, the inorganic and organic parts of creation. The philosophy, as well as theology, of these arrangements have been thus beautifully recorded: Thou coveredst the earth with the deep as with a garment, the waters stood above the mountains; at thy rebuke they fled, at the voice of thy thunder they hastened away into the place thou hast prepared for them. Thou hast set a bound that they may not pass over; that they turn not again to cover the earth.—It is demonstrable that, were all the rocks which compose our mountain ranges and dry land to be dissolved and carried into the sea, the waters of the globe are sufficient again to cover and conceal from view their vast and multiform materials, and to replace them in those depths whence they originally arose.

Dr. Chalmers, in his work on natural theology,[3] has not, we think, correctly apprehended the bearings of the argument for the existence of a God drawn from the fact of the existence of a material world. “We do not perceive,” he says, “how, on the observation of an unshapen mass, there can from its being alone, be drawn any clear or strong inference in favor of its non-eternity: or that simply because it now is, a time must have been when it was not. We cannot thus read in the entity of matter, a prior non-entity, or an original commencement for it: and something more must be affirmed of matter than merely that it is, ere we can discern that either an artist’s mind or an artist’s hand has at all been concerned with it.” Is this either sound reasoning or good philosophy? The fact of the entity of matter does, necessarily and directly, lead to the inference that it had a beginning. It could not originate itself, and just the more as it is viewed in its mere materiality, so much the stronger and irresistible the conclusion that there was no potentiality inherent in itself to cause it to begin to exist. Strip these hills of all their verdure—remove from the mind all consideration of their beauty, variety, and softness of outline—divest that landscape of its ebb and flow of tide—of all that constitutes the scene one of the most charming on the face of the earth, and in its desolation and sterility you would still in idea revert to a period when it was not. These shapeless, inert, barren masses of rock, and soil, and sand, did not place themselves there by any power of their own. Whether on Mount Horeb or Bencleugh, the mind will learn, from its own inner voice, that the traces of Jehovah are there—a Power, beyond and above, that called these rude piles into being—the absence of all form and vitality in themselves the proof and the witness of the Creator’s mind and the Creator’s hand. Death cannot originate anything into life. Matter, as matter, cannot constitute nor begin of itself to be. A scene like this could not now commence its own being, and at no period in the past did it possess a single property of self-existence. The entity and eternity of matter are, therefore, two physically impossible things, as nothing but the one supreme intelligent God can be at once self-existent and eternal, and that which is God cannot be material.

But, if the reasoning here is bad, the philosophy is still worse. It is not philosophy at all to speak of anything in nature as unshapen. Matter is never presented to us in its simple elements. What we see of the visible, material world, is something in combination with something else, substance united with substance, and the union and combination are not accidental or chancework. There are law, order, and definite proportion in every compound body. Things go together by determinate arrangement. When first summoned into being, the elements of the universe had each separately their own communicated properties; they took their places in the mass, each according to their natures; and now the little and the great, the bowlder on the heath and the orbs on high, the concrete rock and our whole planetary system, are modeled upon a plan, and all subservient to a purpose. In decomposition none of them waste or decay. Resolved into their primary atoms, they unite in new arrangements, and collect into new bodies; and in the putrid corrupting mass, the law of order, symmetry, and beauty, reigns in active operation, eliminating new structures and establishing new harmonies.

Men have long been acquainted with the fact, that in all combinations of two or more substances, there are certain proportions which obtain among the different ingredients, and that the best mixtures are those which are regulated according to a scale. The arts have flourished, and improved in one age above those in another, just in proportion as this principle has been attended to, and the degree in which the properties of compounds have been ascertained. We hence learn to imitate the crystal in its clearness, and to rival the colors of gems and flowers. The metals are thus tempered for the use and benefit of society. The acids are neutralized, and salts are formed, and the health of man is restored or preserved. Dalton discovered the law of combination in definite and multiple proportions to be constant in the thin air we breathe—that water, in all conditions and situations, consists of the two ingredients oxygen and hydrogen, and that these in weight are always as eight of the former to one of the latter—that even the most elastic gases are composed of particles of real, ponderable, definable matter—and that through all substances, palpable or impalpable, gross or ethereal, the principle of aggregation, according to the atomic theory, is universal. Science has not, indeed, as yet determined what is the law of connection between the chemical composition and the crystalline forms of bodies; although Sir David Brewster has clearly established that there is an exact correspondence between their optical properties and their crystalline forms,—the law of the transmission of light through specific substances. Sir Isaac Newton had long before cone to the conclusion—and from the heavens brought down a philosophy to explain the theory of the earth—that “All things considered, it seems probable that God, in the beginning, formed matter in solid, massy, hard, impenetrable particles, of such sizes, figures, and with such other properties, and in such proportion to space, as most conduced to the end for which he formed them; and that these primitive particles, being solids, are incomparably harder than any porous bodies compounded of them; even so very hard as never to wear or break to pieces, no ordinary power being able to divide what God made one in the first creation.” Philosophy such as this, verified, much of it, by an induction of rigid experiments, discovers a universe of matter worthy of its author, and like him—a God, not of confusion, but of order; things framed, every one of them, according to rule and method, and all stamped with the indelible impress of utility, design and loveliness. The “unshapen” has no place in the physical world.

“It is not,” continues Dr. Chalmers, “from some matter being harder than others, that we infer a God; but when we behold the harder placed where it is obviously the most effective for a beneficial end, as in the nails, and claws, and teeth of animals, in this we see evidence of a God.”

Now, this is precisely what has been done in the construction and disposition of the several parts of our planet. The hardest matter is placed where it can subserve a beneficial end, on the bottom of the sea, the shores of a continent, the hills that border the valleys of a country. The framework of the globe is in itself of the most durable materials, and these materials have been all so arranged as to render the earth solid, fertile, and beautiful diversity of climate, combined with diversity of soil, moisture, and shelter. These rocks may have been molten in the depths beneath; but no innate powers of nature raised them unto mountains, and separated the hard from the soft, lifting the heavier substance into the highest places, and scooping out the hollows for the lighter. These are acts, all of them, of divine might, directed to a purpose, and what alone could render this world a fitting abode for living things. Wonderfully made are all the creatures of our earth,—every bone, sinew, and muscle in its appropriate place—and so constructed as best to perform their respective functions. But equally wonderful the adjustment and adaptation, through all its parts, of that earth on which they are domiciled, and which ministers so admirably to the various wants and requirements of its diversified tribes of plants and animals. Not more significant of design, nor more effective for a beneficial end, the bony heads and enameled scales of the finny inhabitants of the period, the cephalaspes and holoptychii of the stratified rocks, than the indurated texture of the traps as a solid casement in which their waters were to be retained, and a storehouse of well-assorted materials, whence substance and nutriment were to be extracted for the land. The argument, in short, so far as fitness and utility are concerned, is one and the same in both classes of objects—the house and its inmates alike illustrative of contrivance and skill—equally eloquent in praise of the artist’s mind or the artist’s hand.

And in this way it is, that the story of our earth should be read, and the course of creation should be traced. In the first ordering of things, we see the interposition of a great First Cause; and the farther back we go in our geological researches, the more closely do we discern the chain that connects our globe, and all that is in it, with the throne of the Eternal. The everlasting hills, we are constantly reminded in Scripture, are the witnesses of his power. They are appealed to as the evidences of his ever-active, ever-sustaining presence. What wonderful manifestations of his might and wisdom have they been called to testify! Mount Ararat, the symbol of his saving interposition—Mount Sinai, for the giving of the law, and surrounded with the thunder and terror of his great name—Horeb, proclaiming his mercy and the gentleness of his love—Gilboa, drenched in the blood of his swift vengeance—Hermon, a token of the minuteness of his care and the sweetness of his grace—Tabor, Olivet, and Calvary! scenes of the mystery of incarnation and awful purity of inflexible justice.—And these very hills and mountains around, standing memorials through all ages and their revolutions, that at his bidding they arose, and by his sustaining agency they are still upheld and preserved on high.

We regard as utterly untenable the doctrine, therefore, that from the “entity” of matter we cannot infer the existence of a God. Matter, as mere matter, we do not see, and know nothing of. All the matter that is brought under our notice, is either organized or elaborated into arrangement and disposition of parts, as nicely harmonized and adjusted as organic shape and form.—The organic and inorganic structure may differ, but the difference is one of degree, as much as of kind. The argument, from the existence and composition of the atmosphere, the salubrious mixture of gases in the formation of water, the capacity and adaptation of soils for the germination of seeds and the growth of plants, is equally pointed as to the proof of design and beneficial end, as that which is derived from the fleece of the sheep, the feathers of the bird, and the silicious coating of the wheat-stalk. The uses of these things are obvious, and seen and appreciated at once.—But so is every molecule of matter and aggregation of rock, in the largest amorphous mass as in the polished crystallized gem, assimilated by law and indurated for use. And when we see the structure of the entire globe so directly conducive to the well being of its numerously diversified families, we have the argument the same in the whole as in the parts, in the lumpish mass as in the order and symmetry of the bones, muscles, and organs of the animal frame. But for these hills the rain would fall perniciously, and the dews distill in vain. Of what use the return of the seasons, with no variety of climate? and while the ocean encompassed the globe, where would be the courses of the rivers, the mists and exhalations of the valleys? We may often mistake the uses of things, the end and purpose of particular arrangements; but the doctrine of Final Causes we ought never to leave out of our calculations. They pervade all nature. They permeate all bodies. The world as constituted, the creation which we contemplate and admire, is in all its parts and dispositions a system of means and ends, a combination of instruments end skillfully-balanced agencies, a bright ever-discoursing record of the Eternal Mind, which yet shrouds itself in light inaccessible and utterly unfathomable to the comprehension of all created, finite intelligences, whether human or angelic.

Thus geology takes us up to the beginnings of creation—shows us the ingredients and arrangements of matter—lays bare the foundations of our earthly dwelling, the divisions and conveniences of its apartments—and seeing wisdom in adaptation, design in endurance and suitability, we infer, upon equally irresistible grounds, that the earth is of God, and manifests in everything the perfections of its Author. The scheme of creation, in all its parts and relations, we may never know; its course and order we can distinctly trace through many of its arrangements.

Relative Positions of Trap.

CHAPTER VII.
THE CARBONIFEROUS SYSTEM—PERIOD OF GIGANTIC VEGETABLES.

The system of rocks termed the Carboniferous constitutes the most remarkable, as well as the most valuable, group in the whole range of geological investigation. The strata of which this system is composed, evince design in the clearest and the most unequivocal manner, testifying to the mandate given on the third day of Creation, that the earth was to bring forth grass, the herb yielding seed, and the fruit-tree yielding fruit after its kind; and which, in the prodigious development of vegetable matter that so early and rapidly ensued, demonstrate such productive powers of nature to have been chiefly prospective, and preparatory to the still higher development of life that was to follow.

Milton has finely imagined a tradition in heaven, long subsisting, concerning the creation of a new world, and of man for whose habitation it was intended:

“Space may produce new worlds, whereof so rife,

There went a fame in heaven, that He ere long

Intended to create, and therein plant

A generation, whom his choice regard

Should favor equal to the sons of heaven;

The happy seat

Of some new race, called Man.”

The idea here so beautifully expressed is, that the cosmical arrangements of the earth were, from the beginning, so conducted as to be subservient to man’s well-being; and, certainly, nothing could show more the dignity of the new race, or the interest taken in them by their Creator, than this tradition which ran of them in other spheres. But geology, more to be relied on than poetry, furnishes demonstrative evidence of the anterior designs and purposes of Omnipotent Wisdom in actually fitting up “the happy seat,” and in storing it beforehand with materials suited to the wants and comfortable subsistence of him who was to be its loftiest inhabitant. The coal-metals, in the discovery of their history and position, alone vindicate the importance of geology as a science. The whole group with which they are associated, in their mineral and vegetable contents, their place in the system, and the means provided at once for protection and excavation, manifest a series of contrivances so expressive of design, as cannot fail, when read aright, to draw forth our gratitude and wonder.

I. The Mineral Ingredients, Position, and Arrangement of the Carboniferous System.—The rocks belonging to this formation, in the order of superposition, succeed the old red sandstone, consisting of a series of deposits of great thickness, of an infinite number of alternations and varieties, and nearly the same in every coal-field all over the earth. They constitute one great group of marked physical characters, formed under similar conditions, and produced during the same epoch or period of time. The out-crop of the beds meets the eye along the ridge of which the Lomonds may be taken as the center, ranging eastward by St. Andrews to Fifeness Point, and extending indefinitely westward by Stirling, Campsie Hills, Port-Glasgow, to the coast of Arran. The southern lip of the great coal basin of Scotland stretches from the German Ocean, near Dunbar, to the Ayrshire coast in the North Channel, flanked by the old red sandstone and Silurian rocks almost continuously throughout. And within the space now indicated are situated all the principal coal-fields of the northern part of the empire.

The lower beds of the formation consist generally of coarse-grained sandstone, termed by the English geologists millstone grit, and inclose a few thin unworkable seams of coal. Bands of ironstone, shale, and sandstone are superimposed in repeated alternations. A thick massive limestone lines the edges, feathering in and out through the area of the basin which contains the coal metals. This is the mountain limestone, the most of which is supposed to have once existed as coral reefs, raised on the bottom of shallow seas, so subdivided as to form suitable compartments for receiving and retaining the matter of the coal. Accordingly, corals, encrinites, and shells everywhere prevail in the rocks of this deposit, and, in some instances, present the appearance of a homogeneous, agglutinated mass of the remains of these marine animals—the first of living creatures which the waters were charged to bring forth, and with which they were now swarming. The bituminous beds, the true coal, generally occupy a central position in the group, firmly caked and inclosed between the arenaceous and shaly strata. The number of seams vary in different basins, ranging in Scotland from eleven to thirty-two or thirty-three, and comprising an average thickness of the useful mineral of a hundred and twenty feet. The varieties of coal—as anthracite or blind-coal, cannel or parrot, and the common house or glance-coal—are occasioned chiefly by the different proportions of the bituminous elements which enter into their composition. Compared with Scotland, the coal-measures of England and Wales are of a greater average thickness, lie far beneath the surface, and contain in general a greater proportion of bitumen.

The basin containing the coals, as defined above, is inclosed within the great chains of primary and secondary mountains of the central district of Scotland, which were upheaved into dry land before the coal-measures were formed. A period of violent disturbance had thus passed away, when the carboniferous formation bears evident tokens of having been begun and completed in tranquil waters. But after being collected, the coal-metals were exposed to the action of disturbing forces: eruptive masses, of igneous origin, have invaded their domain; basalts and greenstone, trap dykes and veins, are everywhere found within their inclosure; and apparently the utmost disorder and irregularity now reign, where order and stillness once prevailed. But look a little closer: examine the length and breadth of any coal-field in any part of the world, and you will discern proofs of a purpose, not only in the quality of their materials, but in the position, arrangement, and grouping of the metals; those very disturbing forces, to which they and all earthly things have been exposed, giving unequivocal testimony of an overruling intelligence continuing, through all ages, to superintend and guide their various operations.

Study any coal-field in your neighborhood, and observe the place of the mineral. It does not lie exposed upon the surface, but is placed at a considerable depth in the earth; of which many are apt to complain, thinking that, if a different arrangement had prevailed, much needless labor and expense would have been saved. But the constituent elements of coal are such, that by exposure on the surface the mineral would, in a comparatively short period of time, have run to waste and decay. Even a thick covering of earthy mold would not have been sufficient to protect it; and therefore was the treasure purposely hid in the earth, and so inclosed that the floods could not wash it away. Then consider the quality of the rocks by which the coal is protected, and along with which it is invariably associated. These consist of limestone, sandstone, shale, and clay ironstone, which always occupy the same basins, and alternate with the coal sometimes in a series of more than a hundred beds. Such a group of well-characterized rocks not only act as a guide for determining the localities of the valuable mineral, but they serve the double purpose of facilitating the excavation, by affording at once a safe roofing to the mine, and an easy passage for the drainage of the water which accumulates in the pits. No other class of rocks would have been so suitable. The granite and crystalline rocks would have been inconvenient, or wholly unfit: no borings could have been effected through such materials to any extent; the operations underneath would have been equally difficult and unmanageable; and through such hard compact substances the drainage must have been impracticable. But a still more remarkable indication of contrivance arises from the elevated and inclined position into which the coal strata have been thrown. Had they remained in the position which they originally occupied, and been covered with the vast accumulations which have subsequently taken place, their depth would have been utterly beyond the industry of man to have reached. Hence the waters have disappeared, having accomplished the purpose for which they were, in this instance, spread over the earth, and the rocks formed beneath them have lifted up their heads; not uniformly, or in one continuous unbroken mass, but divided into small sections, and inclined in every possible direction. The wisdom of this appears from two considerations: From their inclined position, the various beds of coal are worked with greater facility than if they had been horizontal, a level is produced for the drainage of the water, and the edges of the coal bent upward are brought nearer the surface. But these advantages are, every one of them, increased incalculably by the division of the coal-field into limited sections, whereby less water is allowed to accumulate than if the beds had been indefinitely extended; their lower extremities are prevented from being plunged to a depth that would be inaccessible; and their several portions arranged in a series of tables, like the steps of a stair, rising one behind another, and gradually inclining outward from the lower to the upper seams of the basin. Again, every coal-field is furnished with a system of checks, in the shape of faults or dykes, against floodings, fire-blaze, and other accidents that occur in the operations of mining. These faults or dykes consist of clay, the detritus of the associated rocks, or of intruded whinstone, with which the fractures produced at the period of the disruption and elevation of the coal-field have been filled up, and the various sections of the metal insulated, and contracted to more workable dimensions. They present the appearance of a vertical wall, cutting the strata at right angles; and, though often occasioning much inconvenience and interruption, yet, as every experienced collier well knows, forming upon the whole his greatest safeguard, and essential every way to his operations. To all which add, as constants in every coal-field, the minerals of lime and iron, gifts, both of them, of inestimable value: the former in the amelioration of the soil and construction of every social edifice; the latter ductile and plastic as wax, capable of being welded, and yet, by a slight chemical change, possessed of adamantine hardness; and the coal always there, in juxta-position, to serve as a fuel for the reduction of the limestone and ironstone into their economic properties—properties starting into agency as if by a miracle.

These are a few of the facts connected with the arrangement and distribution of the coal-measures, in whatever quarter of the globe they are found. Is it possible to resist the conclusion, that, in such a disposition of things, there are the clearest indications of contrivance and design? Nay, that the argument derived from the construction and positions of the solid parts of the earth is the same in kind, if not in degree, with that which is so irresistibly demonstrative in the case of the organic structure of the living frame? The dance of atoms imagined by the philosopher of antiquity, could never have terminated in the perfect order and harmony of the heavenly bodies—innumerable systems of worlds maintained,—each hung upon nothing, and duly preserved all of them in their respective spheres. Equally impossible is it to contemplate a disposition of things so adapted, and indeed so indispensable, for availing ourselves of the mineral treasures of the earth—essential to our wants, and ministering so directly to our social comfort and improvement—and yet to refer the whole, or any part, to the blind operation of fortuitous causes. Impossible, indeed, it ever will be, for the human mind to embrace or unravel all the mysteries of creation; but thus admitted to the mighty wonders of the interior, we are almost enabled to trace the history of the moving atoms from their chaotic disorder into their places and arrangement in the visible universe—to see dead matter assuming the forms of life and organization—clothing the earth for a season with luxuriance and beauty—buried for ages under the solid rock—and again, out of coldness and death, affording light, and warmth, and power to the successive generations of men.

II. Origin of the Carboniferous Rocks.—The strata comprised within the coal-measures are variously estimated; being, in some instances, about eleven thousand feet in thickness; in other cases, of much greater depth; and of this mass of matter, the coal itself does not occupy more than a maximum average of one hundred and fifty feet. The shales consist of thin beds of mud, washed down by the rivers from the neighboring heights, and would appear to have formed the soil on which subsisted a rank vegetation; the impressions of plants, roots, and trunks of trees being still found in a standing position. It is from these bands of mudstone that the best specimens of the flora of the period are derived; every thin splitting presenting the most entire and beautifully-preserved figures of fronds and stems. The ironstone is usually mixed up or associated with the shales, and consists, like them, of comparatively thin beds of ferruginous clay. The sandstones, of which the greater proportion of the mass consists, have clearly resulted in the continued action of the same causes that produced the old red deposit of the anterior period. But the two remarkable products of the age are the calcareous and coaly strata, which give character to the system as well as the epoch in which they were formed; the one showing a sudden development of carbonate of lime, and the other an increase of vegetable matter, whose enduring monuments point them out as the most striking cotemporaneous and co-extensive formations on the surface of the globe, or connected with the history of our planet. The bituminous products of the Silurian period, if the anachronism may be pardoned, are but as the gleanings after the full harvest.

The limestone is unquestionably of marine origin, as the countless myriads of testacea inclosed in it testify, and was probably constructed by the primeval families of those island-making architects by which the coral-reefs of our present seas are raised, and whose instincts have found them similar employment in all ages of the world. The limestones of the earlier systems may have been formed in the same manner; and then, as in the subsequent period, we must go to the great original storehouse of Nature for the materials on which they worked. The spoils of the primary rocks could not supply them, as the quantity of the carbonate of lime therein contained bears no proportion to the masses which constitute the mountain limestone group. But the calcareous substance was already, in some elementary form, in combination or otherwise, in existence—the animals capable of secreting and arranging it anew, as the secondary instruments of creation, were abounding in the seas—shallow bottoms over the subjacent sandstones of the devonian system, and within the required conditions of life, were prepared for their operations. The waters had now brought forth abundantly the moving creatures, which, at first more scantily distributed, produced the limestone of the silurian rocks, as the arborial remains of the land, in like stinted measure, are inclosed in the older palæozoic deposits. Their day of increase as it advanced, each after their kind, is recorded in the vast accumulations of animal and vegetable matter which compose the strata of the carboniferous system, both of an order and quality purposely so arranged, and never upon the same scale of magnitude to be repeated in the combustible mineral.

This account, as given by geologists, of the origin of the mountain limestone, is rendered not only probable, but almost certain, by the manner in which we find these little insects, the coral-builders, constructing their piles of masonry at the present day. For example, certain species of polyps, of solitary habits, work alone, each rearing a single stem or stalk, from which others project; then more stems are produced, until, upon the completion of the whole, there results one of those beautiful arborescent structures so much prized as ornaments for cabinets and drawing-rooms. Some, again, attach themselves to the loose stones, upon which they form their little tree or flower-top; others adhere to the solid rock, from which there springs a stony vegetation, rivaling often, in variety, luxuriance, and brilliancy, the most showy vegetable productions of tropical climes. But a certain class are gregarious, and will only work in company. Myriads of these inhabit the Pacific, constructing entire islands, and throwing up mighty barriers of rock, and threading over vast areas of the sea with inosculating lines of coral reef. The calcareous accumulation, known as the Great Barrier Reef, extends for about a thousand miles in length, by about thirty in mean breadth, filling up, with its various reticulations, the whole intermediate space betwixt the coast of Australia and Bristow Island, off the coast of New Guinea. The works of these minute creatures thus occupy an area which may be roughly estimated at thirty thousand square miles; the different branches forming compartments of variable extent, which are divided into linear, outer, and inner reefs, and embracing within their ample folds the entire spoils of ocean living or floating in these parts.

The mountain limestone of our own country, formed in like manner on the sea-bottom of corallines, has a wide geographical range, extending from the bay of St. Andrew’s on the north, to the extremity of Wales on the south; passing into Ireland, where it is elevated into long ridges, or occupies the mountain-slopes; and forming outliers or extended barriers in all the southern counties of Scotland, and in the greater portion of the northern, the middle, and the south-western districts of England. These were the coral reefs of an ocean now raised into dry land, divided, too, into outer and inner compartments, or arranged into systems of lines and branches, which diverged from or inosculated with each other. Nor does the resemblance between the recent and the more ancient formations stop here, but extends to the structure of the deposits, lithologically considered, the mechanical, sub-crystalline, and crystalline texture being exhibited in both sets of rocks. Thus, in the examination of Heron Island, the coral beds, one to two feet thick, are found to have a tendency to split into slabs, and joints are observed to cross each other at right angles, parallel to the dip and strike, respectively, giving to the still living coral rock the jointings, cleavage, and stratification of the greater palæozoic deposits. Naturalists divide these polyps into existing and extinct races. But whether extinct and specifically different, or otherwise, they are creatures of a family, possessed of the same habits and performing the same operations, now as of old; and if, as geologists say, millions of ages have elapsed between the actings of the first and last generations, our admiration will be only all the more unbounded by thus witnessing the harmony of creation through indefinite time, and the accuracy of the Book which contains the record of it.

The coal itself, as now universally admitted, is of vegetable origin. Under the microscope, in the most compact specimens, the tissues by which all the coal plants are more or less distinguished can be distinctly traced. Chemically considered, its vegetable origin is equally well established. Carbon constitutes the principal ingredient of the mineral the quality of which enters most abundantly into the composition of vegetables. One theory of its formation is, that vegetable matter, carried to the sea or extensive lakes, has undergone a process of decomposition, by which, while some of its principles may have escaped or been evolved in new combinations, the carbon, with a portion of the hydrogen, has remained; this, mixed with more or less earthy matter, has in its soft state been consolidated by the force of aggregation simply, or by compression from the superincumbent strata, and the action of a higher degree of temperature than now exists. Others are of opinion that coal is the altered residuum of trees and smaller plants that have grown on the spot where we now find them—that the forests were submerged and covered by detrital matter, which was upraised to form a foundation and a soil for another forest, to be in its turn submerged and converted into coal—and that thus the alternations which the vertical section of a coal-field exhibits are to be accounted for. The former views are maintained by Sir R. Murchison and other eminent geologists. The latter have been adopted by Sir Charles Lyell, in consequence mainly of the arrangements and structure observed in the remarkable coal-field of Nova Scotia, where he states that there is a range of perpendicular cliffs in the Bay of Fundy, composed of regular coal-measures, inclined at an angle between twenty-four and thirty degrees, whose united thickness is between four and five miles. By neither theory, perhaps, nor by any other yet advanced, is it possible to reconcile all the appearances which that singular compound, a coal-field exhibits—the various changes which the vegetable matter has undergone to convert it into lignite, jet, common coal, cannel coal, and anthracite, two or more of these varieties often occurring in the same coal-measures—in one quarter the clearest indications that the sea has let in its floods and mingled its spoils with those of the land, and in another quarter, through fourteen thousand feet, for example, of the drift accumulations in Nova Scotia, that there is not a trace even of any substance of a marine character, all appearing to have been deposited in fresh water. But while no explanation yet given of the phenomena can be regarded as satisfactory, while Nature withholds much, and ever will, of the wonderful processes through which she attains her ends, the vegetable source of the product cannot be questioned; nay, the origin of coal from the extinct forests, from the trees and plants of a former age, is so very probable, that some beds sound like wood under the beat of the hammer; and large areas, when thin slices are placed under the microscope, are found in every portion to retain the woody-fibrous structure.

III. The Botanical Characters of the flora of the coal period form of themselves an interesting subject of study, and suggest some very important considerations as to the history and purpose of the formation. These will be best understood by a reference to the structure and habits of plants in general. Those of the coal, it will thence be seen, belong exclusively to one or two families,—as ferns, palms, and coniferæ,—which seem to have grown in every soil, and to have been adapted to every climate.

The most general divisions of existing plants are into the vasculares and cellulares. The former kinds all bear flowers, possess a system of spiral vessels, and are termed phonogamous. The latter, on the other hand, are flowerless, have no spiral vessels, and are denominated cryptogamous.

Another extensive subdivision of plants proceeds upon their anatomical structure, and the laws which regulate their mode of growth. Thus one class, it has been observed, increase in bulk by additional increments to the outside of all the parts which compose the plant, as the roots, stems, and branches; another, by additions to the inside of all these members: and for this reason the former are called exogenous, and the latter endogenous. In the one case the new or youngest growth is always exterior to the old; and if thus left unprotected, it will be readily admitted that the growth of all such plants would be greatly and constantly endangered by atmospheric as well as innumerable other causes. The remedy provided by nature against this, is a covering of the substance called bark, which is folded round the entire exterior, stem and branches, of the whole exogens, and within which the newly-formed tissue is all safely deposited. No plant, on the other hand, whose growth is from within, needs any such protection, and accordingly none of them—as all the grasses, corns, canes, and fungi—are possessed of bark, or any analogous membrane. The bark is an ephemeral substance, which lasts only for a year, and has annually to be renewed.

The additions to all exogenous plants are indicated in the stem or trunk, by concentric lines or circles. In the center there is a cellular substance called pith. When you take, therefore, a cross section of the trunk of this class, the structure and parts will be arranged thus—bark on the outside, pith in the center, and between these, concentric deposits of woody matter, and all connected into a solid mass by plates of comb-like tissue, radiating from the interior to the circumference, and termed medullary rays. A structure like this, so closely and firmly united, and filled up through all its parts, was surely intended for endurance; and yet out of this class of the vegetable tribes, nature has selected few of her carboniferous models. The plants of the period, as yet detected, are composed chiefly of cellular tissue, mixed up with the substance of the stem, and without pith, medullary rays, concentric woody deposits, or the binding ligament of bark. The hardy oak and tall slender cane may be taken as examples of the two modes of structure—the former allied to existing, the latter to extinct families.

Another ground of distinction among plants consists in the leaves or flattened expansions, from which they derive all their grace and symmetry. This is farther connected with the seed and rudimentary organs, and gives rise to the division into cotyledonous and acotyledonous plants. The non-flowering or cryptogamous are all of the latter kind. The flowering or phonogamous not only belong to the former, but are again subdivided into monocotyledonous or dicotyledonous, according as their seed-vessels are possessed of one or of two lobes. Where there are two lobes the expansion of the germ upon bursting from the ground terminates in two imperfect leaves, by which the botanist can at once determine the class to which it belongs. The corns and grasses have single cotyledons, from one extremity of which descend the roots, and from the other the stem springs up, terminated with a single leaf.

The leaves perform important functions in all those orders of plants with which they are connected, and serve as interesting guides in fossil botany, which seldom derives any assistance from the more destructible and “fleeting flower.” The leaves of plants consist of a complicated net-work of vessels, filled up in the interstices by cellular tissue, and covered over with a thin epidermis or skin. Those belonging to the monocotyledonous sub-class are traversed by a number of parallel veins, while dicotyledonous leaves are divided into regular compartments, some of which upon withering display the most perfect and beautiful system of reticulation, rivaling in delicacy of texture the wing of the gossamer. Leaves which outlast the season, as in evergreens, are termed non-deciduous, and are covered or interwoven with a thin crust of silex, which at once serves to protect and communicate to these ornamental shrubs their bright enameled appearance. The grasses possess this property, and some of them can elaborate in their joints crystals of considerable magnitude. The leaves of ferns are called fronds, and differ from true leaves in bearing the reproductive organs on the surface, while the slightest inspection of their form and mode of expansion readily distinguishes them from all others. Fronds, properly so termed, originate in the stem and are part of it; there is no distinct line of demarkation between them: stem, leaf, and spori, or seed; are all as one body; and thus, as being of one piece, these membranous organs have been quaintly likened to a garment without a seam.

From this brief description it will be seen that all plants and trees arrange themselves under two great classes, namely, the soft and spongy, or the hard and fibrous-woody structure. The remains of such as have been detected in the carboniferous rocks belong almost exclusively to the former class, the cryptogamiæ and endogenæ, while of the three hundred and upward of fossil species which have been described and figured, not more than ten, and some of these still of doubtful characters, can be regarded as of exogenous and true woody growth. Ferns, mosses, palms, and gigantic succulent plants, now all allied to those of tropical climates, constitute the vast preponderancy of the fossil flora of the age in question. Are we to infer from this that the other families and tribes which at present so abundantly cover the earth were not then in existence? The botanist can now refer to his catalogue of eighty to a hundred thousand species of existing plants, growing in the different regions of the globe, and of widely distinguished habits and forms; and were few or none of these in being then? We possess not, as yet, sufficient data for the solution of this very interesting problem, although in the progress of geological discovery, every year is adding to the list, and giving us a more extended acquaintance with the vegetable products of the coal period. An important experiment recently made by Professor Lindley would seem to favor the probability that a far more numerically abundant flora had then existed. One hundred and seventy plants were thrown into a vessel containing fresh water, and among them were species belonging to all the natural orders of which the flora of the coal-measures consists, and also to other natural orders which it might have been expected would be found associated with them. In the course of two years, one hundred and twenty-one species had disappeared, being entirely decomposed, and of the fifty which remained, the most perfect specimens were those of coniferous plants, ferns, palms, lycopodiaceæ, and the like—the families, all of them, most allied to those preserved in the coal-measures.

Now the important fact to be attended to in this experiment is, the wide geographical distribution during the carboniferous era of those tribes of plants which enter most certainly and abundantly into the composition of the coal metals. Many others may, and doubtless did, flourish within the period of the formation. But that the plants, possessed of the most conservative vegetable qualities, and the most capable of resisting solution in water, should be precisely the kinds which had then a universal range over the earth’s surface, can be ascribed to nothing else than to a wise predetermined purpose and arrangement. These plants were growing in every region. Every clime favored them—every soil nourished them. The bituminous product was intended for man’s use, whose family was destined to inhabit the whole earth. How irresistible the conclusion, corroborative of all the proofs of design derived from the nature and structure of the coal-measures, that, anticipating his wants and providing for his improvement, nature purposely constructed such forms of vegetable life, possessed, like the watch, with a compensation balance so as to suit every condition, and to thrive in every land; or, what is equally probable and consonant to the requirements of the problem, that there was such a uniformity of climate and temperature, and other chemical adjustments, as were most adapted to the peculiar and prevailing vegetation of the period.

IV. The Organic Remains we proceed to consider more in detail, where a remarkable contrast will be observed between the vegetable and animal types presented, so far as they have been respectively fossilized and preserved. The vegetables are nearly all of terrestrial, the animals are as generally and predominantly of marine, characters. Is this the result of blind chance, or of contrivance and foresight?

The plants of the coal epoch consist chiefly of the cryptogamia, and of these the ferns are the most abundant, composing, according to the estimate of M. Brongniart, about two-thirds of the entire carboniferous flora.

1. Sphenopteris linearis; 2. Pecopteris Mantelli; 3. Sphenopteris affinis.

The number of known existing ferns amounts to between seven and eight hundred, of which about fifty species belong to Great Britain, and upward of two hundred to the inter-tropical island of Jamaica. Nearly two hundred fossil species have been discovered in the British coal strata alone. The fossil genera most common to the district around, and occurring in every section of the great valley of the Scottish lowlands, are cyclopteris, neuropteris, pecopteris, and sphenopteris. The shales and clay-ironstones in which these beautiful plants are detected, are generally of a dark brownish color, while the impressions are all of the deepest jet, bringing out in lively contrast the complete cast of the fronds. There is a great resemblance between the specimens of extinct ferns and the existing families of our filices, now growing on every hill, brae, or mountain corrie; and, if this were all the difference, nature would seem to have departed but little from her original models. But the presumption is that most, if not all, the ferns of the coal era were trees which attained to a great height, and similar to the tree-ferns now growing so abundantly in the islands of the Pacific. The decorticated stems and trunks are deeply indented with scars, the markings, it is supposed, of the fronds which dropped from their feathery sides. This inference is borne out by the additional circumstance, that the fossils are generally much flattened and compressed, as would necessarily happen to succulent plants and such trees as consisted of the cellular tissue of the endogenous class. What a striking change in the vegetation of our country, where purple heaths, and cheerful grasses, and luxuriant corns, and forests of every tint and structure, have replaced the long green stems, and dark somber hues of the fern-clad regions of the olden times! The remains of this tribe are so numerous as to have stinted, one would suppose, or utterly to have prevented the growth and increase of every other order of plants, bringing before the imagination the scenes of our Australian colonies, so wild and wondrous to European eyes—and carrying back the mind to the vision of primeval ages, through a long succession of times and their events, the vista of an infant world.

The lycopodia, or club-moss tribe, are also very widely distributed among the coal-measures, and attained in the earlier ages of the earth’s history an equally gigantic size with the tree-ferns. At the present day, they are all weak, prostrate plants, of from two to three feet in length, and, following the same laws as the mosses and ferns, they are most abundant in hot, humid situations within the tropics, and especially in the smaller islands. As respects their botanical affinities, the lycopodiums are intermediate between ferns and coniferæ on the one hand, and ferns and mosses on the other; related to the first of those families in the abundance of annular ducts contained in their axis, and to the second in the whole aspect and outline of the stem of the larger kinds. Indeed, so great is the resemblance between lycopodia and certain coniferæ, that there is no other external character, except size, by which they can be distinguished; and, according to Professor Lindley, it is, at least, as probable that some of those specimens detected in the ancient flora of the world, which have been considered gigantic club-mosses, are really and truly pines, as that they are flowerless plants.

Another family of fossil plants abundant in the coal formation are the calamites, so named from their jointed reed-like structure. They attained to the size of trees, trunks upward of a foot in diameter being often met with, but still of such a soft succulent texture as to maintain the character of being, if reeds, easily shaken by the winds. These, and various specimens of the palm tribe, are to be found in every coal-field, and often in such vast masses as to show that they constituted no inconsiderable proportion of the flora of the period. Palms now only flourish within the regions of the tropics, where, from their various properties, as well as great productiveness as fruit-bearers, they constitute the chief source of dependence to the inhabitants for all their supplies of the necessaries, luxuries, and medicines of life. A single spathe of the date contains about 12,000 male flowers: another species has been computed to have 207,000 in a spathe, or 600,000 upon a single individual. The spathe constitutes the raceme or flower-stem of the tree, and on a single raceme of a Seje palm, Humboldt estimated the flowers at forty-four thousand, and the fruits at eight thousand. When these magnificent productions of nature covered the plains and marshes of our northern climes, there were no roaming tribes to gather their fruits, inhale their fragrance, or bask in their shades. And yet they were not formed in vain. Buried in the rocks, their collected remains now yield a product as useful and valuable to the human family—as contributive to intellectual improvement, as they would have been to mere animal enjoyment.

The genus sigillaria, one of the most common of the coal plants, possessed the singular properties of being apparently hollow in the center, yet with an inner woody axis floating in a woody succulent jelly, and inclosed in a thick outer coating of bark. The trunk is beautifully fluted with longitudinal parallel lines, regularly arranged along the surface, and dotted all over with small scars, as if impressed by the leaves penetrating through the bark into the central woody axis. The stigmariæ, once supposed to be a distinct genus, are now generally regarded as simply the roots of the sigillariæ; they are, for the most part, found resting in their natural position, in large clusters often; and forming with their dense matted fibers a floor of considerable thickness, on which, season after season, the leaves fell as the coaly matter accumulated. This tree grew to an enormous size, specimens of four feet in diameter by fifty feet in length being frequently met with; traces of a vascular and fibrous structure can be observed in the stems—also the annular wood layers are sometimes beautifully defined; and, combined with a coating of bark of an inch in thickness, the probability is, that the sigillaria belonged to the exogenous class of vegetables.

Calamite.

But of all the plants found in the coal-measures, the coniferæ or pine tribe, distinguished by their punctated woody tissue, are the most interesting, whether we consider their characteristic properties, extensive distribution, antiquity, and consistency of habit through all the epochs and changes of creation. Unlike the tree-forms already noticed, the pines grow now as they grew before, inhabiting the same places, and preserving the same appearances in bulk and figure. In structure the coniferæ occupy a place intermediate between cellurares and vasculares, connected with the former through the lycopodiums, and with the latter by the myriceæ, or aromatic gale tribe. The scales of the cones are regarded by botanists as true foliage or reduced leaves, and in this respect they approximate to the genus zamia, of the order cycadeæ, where these organs are distinctly developed as carpellary leaves. Thus widely connected through the chain of vegetable life, the fossil pines, discovered in our coal-fields, form also the most interesting link between the present and the remote past, showing similar conditions of vegetable existence and forest landscape. No class of plants have been more useful to man than the whole pine family; none are more universal in their distribution over the face of the globe; none are possessed of such powers of endurance, existing through all time, and natives of every part of the world, from the perpetual snows of Arctic America, to the hottest regions of the Indian Archipelago. These trees differ as remarkably in form as in size, ranging through every gradation from the stinted juniper of the Grampians to the stately cedars of Lebanon. And the fossil specimens, huge in dimensions as those of Craigleith are, do not excel the existing races. The araucaria, or Norfolk Island pine, attains a height of two hundred feet; and in the Oregon territory of North-West America, there are species of the fir tribe (P. Lambertiana and P. Douglasii), which rise to even still more gigantic proportions. Figuratively, it is said of the cedar, that its branches shall cover the earth, and in the shadow thereof all fowl of every wing shall dwell: literally and truly we find, that members of the same family have existed in all lands, and flourished in the mountains through all ages.

Compared with the present condition of things, New Zealand bears the most striking resemblance in the character of its vegetation to the flora of the ancient carboniferous age. “The number of species of plants at present known is 632, of which 314 are dicotyledonous, and the rest, or 318, are monocotyledonous and cellular. The number of monocotyledonous is very small in comparison with the cellular; there are 76 species. The grasses have given way to ferns, for the ferns and fern-like plants are the most numerous in New Zealand, and cover immense districts. They replace the gramineæ or grasses of other countries, and give a character to all the open land of the hills and plains. Some of the arborescent species grow to thirty feet and more in height, and the variety and elegance of their forms, from the minutest species to the giants of their kind, are most remarkable.”[4]

These few types of the flora of the ancient world clearly indicate the course and progress of creation. A dense vegetable covering already existed over all the earth. No grasses, indeed, as yet are found to have clothed the plains. But marsh plants grew luxuriantly in the waters. Fucoids and algæ abounded in the seas. The hills and mountains raised high in air their pines, palms, and fern-trees; nor would creepers and parasites be wanting, climbing to their topmost branches and mingling their bright enlivening hues with the dark somber shades of the forest. Earth heard the voice of its Maker, and everything good and seasonable sprang from its teeming bosom.

The carboniferous limestones are everywhere loaded with animal remains. Every member of the series, the ironstones, sandstones, shales, and even the coal itself, all abound in relics of the past; and, as was to be expected, the fossils chiefly belong to marine forms of life. And in these there is no great departure, as might likewise be inferred, from the orders, and even generic types, we have been surveying in the lower formations. But there is an increase in the species of some of them, as well as the introduction of new and distinct creations altogether.

1. Product. scabriculus; 2. Inoceramus vetustus; 3. Bellerophon tangentialis.

Thus the corals and encrinites remain with scarcely a change in outward form, but of increasing variety, and in countless myriads. The trilobites are nearly extinct, while the annelidæ, which appear not in the devonian system, return to the stage in greater numbers and diversity of structure. The conchiferæ are likewise enlarged in every order; as also the crustaceæ, which are more than quadrupled. Pteropodæ present four genera in the silurian group, decline to one in the devonian, which genus is not found in the carboniferous, but a new one takes its place. The brachiopodæ are again very abundant, as they were in the two former groups. The most characteristic shells of the order and period are the productus, spirifer, terebratula. One genus of heteropoda, the bellerophon, appeared in the silurian rocks, of which there were eleven species. Eight species occur in the devonian system along with a new genus, porcellia. The bellerophon numbers nineteen species in the carboniferous rocks, and the porcellia, which occurs also, contains three.

The cephalopods, the most predaceous of their kind, lose generically, while they multiply prodigiously in species during the latter epoch. Thus the goniatites alone amount to fifty-four, the nautili to forty-two, and the orthoceratites, which had declined to twelve in the devonian, swell to thirty-two species in the carboniferous series.

But the fishes in this group of rocks exhibit, unquestionably, the largest amount, both in number and form, of new types. Here the sharks and sauroids appear, for the first time, not small, or attenuated in bulk, but vigorous, robust specimens of their kind, strong and expert swimmers, armed with enlarged destructive organs, and every way equipped for maintaining the due proportion of numbers, and the free trade of the ocean. Thus of the order of placoids, there are twenty-eight genera, and ninety-four species; of ganoids there are five genera, and twelve species; and sauroids enumerate thirteen genera, and twenty-four distinct and entirely new specific creations. A specimen of reptilian life has here also been detected; and what is of still greater theoretic importance, in tracing the course of creation, the immediately overlying sandstones have yielded up impressions of the winged tribes that “fly in the open firmament of heaven.” This interesting fact will, in its proper place in the order of superposition, be more fully alluded to.

The genus holoptychius, which began in the old red sandstone, again occurs in the carboniferous system, under eight new specific forms. Along with the megalichthys, afterward noticed, these constitute the two great natural families of fishes of carnivorous propensities, which give a marked character to the period. The prodigious increase of the shark-like creatures, of which not less than sixty species have been described from thousands of teeth, fins, detached vertebræ, and other fragments, is equally striking. Thus, in all, the faunæ of the carboniferous period amount to upward of a thousand species, which have been either figured or described.

In contemplating the period of creation under review, we are struck not more with the forms of life which actually existed, than with the absence of races which were afterward so abundant. No quadruped or true terrestrial animal is found so low in the series of rocks, or mixed up in any way with all this profusion of marine exuviæ. Fossil insects and indications of other winged tribes have been detected; but no bone nor foot-print of beast, or inhabitant of land, has anywhere been discovered. The fact is all-important, as showing not only a plan, but a progress and succession in the work of creation. A vegetation, so rank and luxuriant as has been traced, trees towering hundreds of feet into the sky, and branches of the densest foliage stretching on every side, was amply fitted to afford shelter and food to families of terrestrial creatures of every kind. But in the circumstance, that during this period there were repeated alternations of marine and fresh water deposits, and consequently repeated submergence and elevation of land, we see a reason why the terrestrial races were not yet called into being. Great continents, comparatively speaking, did not exist; and there was no ark of safety provided to float them over the billows. Race after race would have violently perished during every shift or subsidence of the sea bottom: and hence, until the carboniferous series was completed and a statical equilibrium established between the land and waters, few or none of the races which afterward swarmed in our plains and forests were introduced upon the scene.

Fragment of Encrinital Limestone.

CHAPTER VIII.
GEOGRAPHICAL DISTRIBUTION OF COAL—GREAT COAL FIELD OF PENNSYLVANIA, VIRGINIA AND OHIO—COAL DEPOSITS OF ILLINOIS, INDIANA AND KENTUCKY—ECONOMIC HISTORY—CONDITIONS OF FORMATION.

Considered mineralogically, and now demonstrated beyond a doubt, coal and the diamond are found to be one and the same in substance, and nearly also in their modes of formation. Newton detected the properties of the diamond in its refractive power over the rays of light, and inferred that, like amber, it was an unctuous body crystallized. In the crucible he reduced it to a state of pure carbon, burning, volatilizing, and resulting in the same elementary products as charcoal. Liebig goes a step farther, and declares the diamond to be a crystalline residuum from decayed vegetables. The action of fire could not produce the mineral, but would rather have the effect of drawing out its inflammable tendencies. “Science,” he adds, “can point to no process capable of accounting for the origin and formation of diamonds, except that of decay. And there is the greatest reason for believing that they have been formed in a liquid.” Sir David Brewster, in his beautiful optical analysis, has arrived at the same general conclusions.

Coal is also a product of vegetable decay, collected and formed in a liquid. It has not crystallized, and therefore wants the sparkle and the luster of the diamond. It retains all the carbon, and more of the hydrogen, and is in consequence infinitely more useful and valuable than even the precious gem. It is carefully incased and preserved among the rocks of the earth, and thereby in like manner akin to the glittering idol, whose true habitat has been found to be the sandstones[5] immediately overlying the carboniferous formation. Thus far the parallel can be traced between the two apparently very dissimilar and unequally prized minerals: in extent of substance and geographical distribution, the history of each stands apart.

I. The Geographical Distribution of the Coal Metals.—Our knowledge on this subject is increasing with every new geographical detail connected with the history of the earth. Until very recently the carboniferous system was supposed to be of very limited extent. The return of every vessel, engaged in a voyage of discovery or otherwise, brings tidings of some new island or continent on which it is found. The same tribes of plants and animals are everywhere observed to accompany the deposit—all presenting the same generic and often the same specific characters—and uniformly on the same great scale of development. This circumstance alone bespeaks a universal formation, when every region was capable of producing all the requisite conditions in climate, vegetables, corallines, and sea-bottom, and prepares the mind for the ready admission of the existence of the mineral in every unexplored quarter of the globe. Accordingly, all the great continents of the old world abound in coal. In Russia, the carboniferous system occupies, betwixt the Dnieper and the Don, an area of about eleven thousand square miles. India, China, and the Australian archipelago give up yearly more and more of the bituminous substance. Egypt is not destitute of the jetty mineral: for recently beds several feet thick have been discovered near Asuan, on the right bank of the Nile. The vast continent of America has it in proportion to its own vastness. And man, go where he will with the knowledge of the arts, and the diffusive blessings of religion and civilization, will always find that a wise Providence has anticipated his wants, and prepared the treasure for his use.

The coal formation in Scotland has been already traced as occupying the great central valley of the Lowlands, which separates the primitive crystalline and feldspathic rocks of the north from the silurian series of the southern border, and traversing the mainland from sea to sea. The middle and northern coal basins of England have an average uninterrupted stretch of about two hundred miles in length, by forty in breadth. The Bristol and Welsh coal-fields, are also very extensive. That of South Wales forms an immense double trough, comprised within a great oval elongated tract, betwixt St. Bride’s Bay, and Pontypool, with an anticlinal axis ranging east and west, and embracing an area of one thousand and fifty-five square miles. This is the largest coal-field in Britain, in which there are sixty-four seams of coal, of all qualities, from the highest bituminous to the purest anthracite, and having an aggregate thickness of one hundred and ninety-feet. In Ireland the coal basins are comparatively small, and isolated from one another: the principal workable seams are in the counties of Kilkenny, Tipperary, Cork, Tyrone, and the northern extremity of Roscommon.

The coal metals immediately present themselves on the French coast at Boulogne, more inland at Mons, and in the central district at St. Etienne, betwixt the valleys of the Loire and Rhone. This last basin is of small extent, but possesses great geological interest from its position among the primary and metamorphic rocks, and the materials of which the series is composed. The metals are inclosed in a long narrow trough, of about twenty-five miles by less than a mile at its greatest breadth. Granite, gneiss, mica-slate, underlie them throughout: instead of shales, and sandstones of the usual kind, the coals are imbedded in micaceous grit, and the detrital alluvia of the crystalline rocks. It has been described as a self contained repository, with its own furnishings and equipments all, as it were, self-originating: the vegetable matter is of native growth, the trees are still vertical, and in one part of the field present the appearance of a suddenly petrified forest; the iron, too, is native, and seems to have been actually smelted on the spot, by subterranean self-combustion. The coal, underlying one of the bands of ironstone, has undergone fusion, and been changed into coke; while sulphur and crystals of sulphate of lime have been separated in the crucible by the process of sublimation, as if to complete this scene of marvels.

In the low countries, at Namur and Liege, and other places along the banks of the Meuse—in Germany, Silesia, Moravia, Poland, the Carpathian Mountains—on the banks of the Volga, the Dnieper, and the Don, the coal-measures are found to occupy tracts of greater or lesser extent. These are sometimes accompanied with the usual alternating series entire and unbroken, sometimes with the absence of one or more members. In Russia the metals are imbedded in the middle mountain limestone series in one field, while in another district they are situated in the lower part of the series, or beneath the calcareous deposit, as in the thin beds of Fifeshire. The Liege coal-basin is of a remarkably complex structure—the metals lying in small hollows of contorted strata, which are bent and twisted like a sapling—elevated into every varying position and degree of inclination—and thus, by obtaining cross or horizontal sections, you pass repeatedly over the edges of the same beds. An enterprising Scotchman has long been lessee of one of these coal-fields, out of whose iron bands he has molded cannon and ball for every nation in Europe; and whose locomotives, forged from the same strata, now ply in pleasure excursions along every railway of the Netherlands and vine-clad banks of the Rhine and Moselle.

The American coal-fields, like its interminable forests, endless rivers, and everything in that vast continent, are all on the gigantic scale. The basin of the Mississippi, extending from the Rocky Mountains to the Alleghanies, forms an area equal to two-thirds of the states of Europe, almost every part of which is covered with the carboniferous limestone, supporting the coal metals and the newer palæozoic rocks. The great coal-field of Pennsylvania, Virginia, and Ohio, extends, according to Sir Charles Lyell, continuously from north-east to south-west for a distance of 207 miles, its breadth being in some places 180 miles. The basin of Illinois, Indiana, and Kentucky, is not much inferior in dimensions to the whole of England, while another coal deposit, 170 by 100 miles, lies farther to the north, between lakes Michigan and Huron. Mr. Logan, in his report on the geology of Canada, states that the coal-measures occupy nearly the whole of New Brunswick, a great part of Nova Scotia, Cape Breton island, and the south-west district of Newfoundland. And in the most remote northern regions, along the shores of the frozen sea, and the various rivers and their tributaries which fall into it, the carboniferous rocks with their inclosed beds of coal, some of considerable thickness, are found to prevail. A single seam, of an average thickness of ten feet, occurs in Pennsylvania, in the district of Pittsburgh, covering a superficial extent of about 14,000 square miles; which shows how inexhaustible the resources, and how limitless the means, of social advancement, of progress in the arts and sciences, garnered up for the generations to come in that mighty continent.

Upon the authority of Sir Charles Lyell we learn, that all the floral fossil phenomena are substantially the same as in Europe—a great preponderance of stigmariæ, ferns, lepidodendra, and calamites—some consisting of trees in an erect position, and of broken trunks, with their rootlets attached, and extending in all directions; and the same grits or sandstones, are found, as those used for building near Edinburgh and Newcastle. Of forty-eight species of fossil plants or trees, detected in the strata of Nova Scotia, thirty-seven are identical with those discovered in the British beds; and, in the United States, thirty-five out of fifty-three species are described as specifically the same with the European fossils. But the most remarkable of Sir Charles’s discoveries is that, in the prodigious thickness and singular structure of the coal-basin in Nova Scotia, there are the remains of more than ten forests which rose up successively one over the other, and which, with their interposed layers of clays and solid stone, deposited at intervals, constitute a series of beds, whose vertical thickness is 14,570 feet.

II. The Economic History of Coal.—It does not appear, from any well authenticated records, at what precise period man availed himself of this useful mineral, either for the purposes of art, or of domestic comfort. The early history of nations is traditionary; but there is no tradition from very remote times, in any of them, as to the discovery of coal—no philosopher speculating about the importance of the fact and its bearings on the progress of civilization—no poet extolling the genius of the new Prometheus, that brought up the fiery combustible from the bowels of earth. The aborigines who dwelt amidst the primeval forests had no occasion to seek farther for fuel, when every hill and plain supplied them with all that was needed, and more than was convenient, as the cultivation of the soil engaged attention. Accident, doubtless, would first lead to the knowledge of the virtues of the hidden treasure. As the ground was cleared, and cities became populous, and the arts advanced, more diligence would be exercised in its search; and in proportion as it came, from the destruction of the woods, to be regarded as a necessary or luxury of life, coal would be sought for as an article of barter, or of commerce. Thus many ages might elapse before coal was introduced into general consumption, and though stored up specially for man, it was wisely ordered that the supplies and incumbrances on the surface should first be exhausted or removed, ere the inner chambers of his habitation were broken into and explored.

Bituminous matter, if not the carboniferous system itself, exists abundantly on the banks of the Euphrates. In the basin of the Nile coal has been recently detected. It occurs sparingly in some of the states of Greece: and Theophrastus, in his “History of Stones,” refers to mineral coal (lithanthrax) being found in Liguria, and in Elis, and used by the smiths; the stones are earthy, he adds, but kindle and burn like wood coals (the anthrax). But by none of the oriental nations does it appear that the vast latent powers and virtues of the mineral were thus early discovered, so as to render it an object of commerce or of geological research. What the Romans termed lapis ampelites, is generally understood to mean our cannel coal, which they used not as fuel, but in making toys, bracelets, and other ornaments; while their carbo, which Pliny describes as “vehementer perlucet,” was simply the petroleum or naphtha, which issues so abundantly from all the tertiary deposits. Coal is found in Syria, and the term frequently occurs in the sacred writings. But there is no reference anywhere in the inspired record as to digging or boring for the mineral—no directions for its use—no instructions as to its constituting a portion of the promised treasures of the land. In their burnt-offerings, wood appears uniformly to have been employed; in Leviticus, the term is used as synonymous with fire, where it is said that “the priests shall lay the parts in order upon the wood, that is, on the fire which is upon the altar.” And in the same manner for all domestic purposes, wood and charcoal were invariably made use of. Doubtless the ancient Hebrews would be acquainted with natural coal, as in the mountains of Lebanon, whither they continually resorted for their timber, seams of coal near Beirout were seen to protrude through the superincumbent strata in various directions. Still there are no traces of pits or excavations into the rock to show that they duly appreciated the extent and uses of the article. Their term גחל, which properly signifies charcoal, appears to have passed into the northern languages, as in the Islandic gloa; the Danish gloe; the Welsh glo, a coal, golen to give light; the Irish o-gual; and the Cornish kolan—terms all expressive of the act of burning or of giving light.

For many reasons it would seem that, among modern nations, the primitive Britons were the first to avail themselves of the valuable combustible. The word by which it is designated is not of Saxon, but of British extraction, and is still employed to this day by the Irish, in their form of o-gual, and in that of kolan by the Cornish. In Yorkshire stone hammers and hatchets have been found in old mines, showing that the early Britons worked coals before the invasion of the Romans. Manchester,[6] which has risen upon the very ashes of the mineral, and grown to all its wealth and greatness under the influence of its heat and light, next claims the merit of the discovery. Portions of coal have been found under or imbedded in the sand of a Roman way, excavated some years ago for the construction of a house, and which, at the time, were ingeniously conjectured by the local antiquaries to have been collected for the use of the garrison, stationed on the route of these warlike invaders at Mancenion, or the Place of Tents. Certain it is, that fragments of coal are being constantly, in the district, washed out and brought down by the Medlock and other streams, which break from the mountains through the coal strata. The attention of the inhabitants would, in this way, be the more early and readily attracted by the glistening substance.

Nevertheless, for long after, coal was but little valued or appreciated, turf and wood being the common articles of consumption throughout the country. About the middle of the ninth century, a grant of land was made by the Abbey of Peterborough, under the restriction of certain payments in kind to the monastery, among which are specified sixty carts of wood, and as showing their comparative worth, only twelve carts of pit-coal. Toward the end of the thirteenth century, Newcastle is said to have traded in the article, and by a charter of Henry III, of date 1284, a license is granted to the burgesses to dig for the mineral. About this period, coals, for the first time, began to be imported into London, but were made use of only by smiths, brewers, dyers, and other artisans, when, in consequence of the smoke being regarded as very injurious to the public health, Parliament petitioned the king, Edward I, to prohibit the burning of coal, on the ground of being an intolerable nuisance. A proclamation was granted, conformable to the prayer of the petition; and the most severe inquisitorial measures were adopted to restrict or altogether abolish the use of the combustible, by fine, imprisonment, and destruction of the furnaces and workshops! They were again brought into common use in the time of Charles I, and have continued to increase steadily with the extension of the arts and manufactures, and the advancing tide of population, until now, in the metropolis and suburbs, coals are annually consumed to the amount of about three millions of tons. The use of coal in Scotland seems to be connected with the rise of the monasteries, institutions which were admirably suited to the times, the conservators of learning, and pioneers of art and industry all over Europe, and in whose most rigorous exactions evidences can always be traced of a judicious and enlightened concern for the general improvement of the country. Under the regime of monastic rule at Dunfermline, coals were worked in the year 1291—at Dysart, and other places along the coast, about half a century later—and, generally, in the fourteenth and fifteenth centuries the inhabitants were assessed in coals to the churches and chapels, which, after the Reformation, have still continued to be paid in many parishes. Boëthius records that, in his time, the inhabitants of Fife and the Lothians dug “a black stone,” which, when kindled, gave out a heat sufficient to melt iron.

How long will the coal-metals of the British isles last at the present, or even an increased expenditure of the fuel? So great has been the discrepancy, and so little understood the data on which to form a calculation, that the authorities variously estimate from two hundred to two thousand years. For home consumption the present rate is about thirty-two millions of tons annually. The export is about six millions: and yet such is the enormous mass of this combustible inclosed in one field alone, that no boundary can be fixed, even the most remote, for its exhaustion. The coal trade of Great Britain is nearly in the proportion of three to two of that of all the other nations of the world; while in superficial area her coal measures are to those of the United States only as 11,859 square miles to 133,132 square miles. What a vision of the future is hereby disclosed! If rightly employed, if the arts and progressive development of society at all keep pace with the means provided, the human race in the New World have a destiny to run, and a work of civilization to accomplish, to which the Old, in its brightest achievements, can furnish but a faint analogy. Scarcely two centuries have elapsed since coal was employed as an article of domestic use, or introduced upon the most limited scale into the manufactures; its now ascertained extent and boundless latent powers were not dreamt of or imagined even but half a century ago; and very recently the lamentation was general, that no coal-measures existed in the mighty continent of America. Who now can fancy a limit to the social movement with which that vast hemisphere is heaving all over—the advancing tide of its population spreading in every region—the forests cleared and covered with a net-work of railways, the rivers bridged from end to end with a navy of steamships—and all vivified and in motion through the agency of this long undiscovered product of the earth? Geological time rolled on, and the surface of our planet was replenished with the hidden treasure, and the man of science has no numbers to reckon the years that are past. More agreeable far to look through the vista of coming events, where a moral era has commenced out of which a mightier series of phenomena will emerge, the purposes of a wise Providence be illustrated in so transmuting and preserving the entombed relics of distant ages, and the glories of the latter day arise, when the desert place shall teem with a new life, and the wilderness give praise to the Creator of all.

III. Universal, and shall we add, synchronous as a formation, there is a very interesting question connected with this subject, namely, is coal now forming? The general opinion among geologists leans to the affirmative side of the question, and that here, as in all the other cosmical arrangements going forward on the earth’s surface, time is the grand requisite. The necessary agencies are all at work, the other conditions are all admitted, and in the course of some future untold ages a new bituminous product will arise, similar in all respects to the old. The subject and the conclusions arrived at are not, however, free of many and great difficulties, to some of which we shall merely advert.

Reverting to all the circumstances connected with the geographical distribution of the coal metals, we are inclined to think that the era which produced them was not only peculiar in the wide geographical distribution of its families of plants, but equally, if not more so, in its limitation of all those physical conditions which were necessary for their conversion into coal. The basins, it will be observed, in which the vegetable matter was deposited, were, as compared with the existing ocean, small and shallow; for most of the plants and trees grew within their area or their immediate neighborhood, and are still found in their erect position, uninjured by roughing or transport in their smallest veinlets and even minute fructifications.

Then it is highly probable, that the great continents were not yet formed, but that a series of islands, barrier reefs, and inland seas, prevailed generally over the earth’s surface, being still chiefly oceanic. Consequently no great rivers could, in such circumstances, be in existence, rolling down like the Ganges, Nile, and Mississippi more stony detritus and mud than arborescent matter, and all to be mixed and confounded in one indiscriminate mass. Atmospheric influences, too, must have been widely different from what they now are; for all the cast-off apparel of a summer’s luxuriance is, we see year after year, speedily dissipated by the droughts, or absorbed back as humus into the earth, and when spring returns the ground is parched and bare. A difference of temperature must also be taken into the list of modifying causes; for the plants, during the coal era, are nearly of a class—a few great types with little variety of structure—one and the same in every region—and approaching the characters, most of them, of the existing tropical flora. The climate, according to Mr. Bunbury, was characterized by excessive moisture, by a mild and steady temperature, and the entire absence of frost; and it has been established by Mr. Darwin’s interesting observations on Chiloe and other islands of the southern temperate zone, that extreme heat is not necessary to the existence of a very luxuriant and quasi-tropical vegetation. Mr. Austen, on the other hand, thinks that the temperature of Great Britain has not much changed since the coal period, because few of the fossil-ferns, found in the coal-measures, present any fructification, while those in more southern latitudes possess it; and, by experiments made by himself, it appears that the existing ferns of tropical climates would not fructify at a low temperature. Still, the great general fact remains unquestioned, that tree-ferns during the carboniferous age grew gigantically and in vast forests, where they do not grow at present over all the zones of the earth; and where now growing, in three out of the four zones, that the whole family are reduced to the size of small herbaceous plants.

Now, is it not a legitimate inference from all this, that, out of so many concurring circumstances, not one of which is similar in all respects now, a determinate effect was intended to be produced, and which cannot, in the altered condition of things, be produced again? The argument is cumulative, and bears the strongest presumptive evidence on its side. The carboniferous series cannot be repeated—not for want of vegetable or animal matter, for there is a hundred times more of both at present on the surface of the earth than perhaps ever existed in any former period—but because there are so many new causes now in operation, so many changes in the relative position of sea and land, to modify its distribution and qualities, and to influence its place in the system generally, that the same conservative arrangements and chemical appliances cannot occur, nor any similar bituminous compound as a geological formation issue from Nature’s laboratory.

Leonard Horner, in enumerating the difficulties connected with the formation of the coal deposit upon the theory of the whole of the matter, vegetable and earthy, being spread over the sea-bottom, says—“That the terrestrial vegetable matter, from which coal has been formed, has in very many instances been deposited in the sea, is unquestionable, from their alternations with limestones containing marine remains.” Such deposits and alternations in an estuary at the mouth of a great river are conceivable; but whether such enormous beds of limestone, with the corals and molluscs which they contain, could be formed in an estuary, may admit of doubt. But it is not so easy to conceive the very distinct separation of the coal and the stony matter, if formed of drifted materials brought into the bay by a river. It has been said that the vegetable matter is brought down at intervals, in freshets, in masses united together, like the rafts in the Mississippi. But there could not be masses of matted vegetable matter of uniform thickness, 14,000 square miles in extent, like the Brownsville bed on the Monongahela and Ohio (the Pittsburgh seam): and freshets bring down gravel, and sand, and mud, as well as plants and trees. They must occur several times a year in every river; but many years must have elapsed during the gradual deposit of the sandstones and shales that separate the seams of coal. Humboldt tells us (“Cosmos,” p. 295),—That in the forest lands of the temperate zone, the carbon contained in the trees on a given surface would not, on an average of a hundred years, form a layer over that surface more than seven lines in thickness. If this be a well-ascertained fact, what an enormous accumulation of vegetable matter must be required to form a coal-seam of even moderate dimensions! It is extremely improbable that the vegetable matter brought down by rivers could fall to the bottom of the sea in clear unmixed layers; it would form a confused mass with stones, sand, and mud. Again, how difficult to conceive, how extremely improbable in such circumstances, is the preservation of delicate plants, spread out with the most perfect arrangement of their parts, uninjured by the rude action of rapid streams and currents, carrying gravel and sand, and branches and trunks of trees?”

Nor, according to Mr. Horner, are the objections to the lacustrine theory, requiring so many oscillations of land and water, of less magnitude. “In the theory,” he says, “which accounts for the formation of beds of coal, by supposing that they are the remains of trees and other plants that grew on the spot where the coal now exists, that the land was submerged to admit of the covering of sandstones or shale being deposited, and again elevated, so that the sandstone or shale might become the subsoil of a new growth, to be again submerged, and this process repeated as often as there are seams of coal in the series—these are demands on our assent of a most startling kind. The materials of each of these seams, however thin (and there are some not an inch thick, lying upon and covered by great depths of sandstones and shales), must, according to this theory, have grown on land, and the covering of each must have been deposited under water.—There must thus have been an equal number of successive upward and downward movements, and these so gentle, such soft heavings, as not to break the continuity, or disturb the parallelism of horizontal lines spread over hundreds of square miles; and the movements must, moreover, have been so nicely adjusted, that they should always be downward when a layer of vegetable matter was to be covered up; and, in the upward movements, the motion must always have ceased so soon as the last layers of sand or shale had reached the surface, to be immediately covered by the fresh vegetable growth; for otherwise we should have found evidence, in the series of successive deposits, of some being furrowed, broken up, or covered with pebbles or other detrital matter of land, long exposed to the waves breaking on a shore, and to meteoric agencies. These conditions, which seem to be inseparable from the theory in question, it would be difficult to find anything analogous to in any other case of changes in the relative level of sea and land with which we are acquainted.”

While these statements show that we are still but imperfectly acquainted with all the conditions and circumstances under which coal was formed, two deductions may be made from them, not only as against the rival theories themselves, of Murchison and Lyell, but still more strongly against the application of either theory to existing causes in the formation of the true bituminous product. In the first place, the vegetable matter brought down by the rivers, and spread over the bottom of the sea, does not amount to an infinitesimal fraction of what constitutes the enormous compound of the carboniferous age; and a different effect, according to the laws of nature of which we have experience, will necessarily result from the causes now in operation. Secondly, whatever, as a question of fact, it may have been with our coal-basins in the times gone by, certain it is that NOW there are no such oscillatory movements, causing the required changes in the relative level of sea and land, in those quarters of the globe the most densely covered with forests and jungle, and out of which the new coal-measures are expected to rise. The thin accumulations of woody residuum, observed by Sir Charles Lyell, in the sections exposed along the banks of rivers, railways, and other passages through American prairies and forests, are all unfavorably circumstanced—firm as the everlasting hills on their rocky foundations.

We may be reminded of the numberless ages required for the production of coal, that man’s experience is but of yesterday, and himself an ephemeral of a moment as compared with the revolutions of time recorded on the fabric of the globe. This record, we have reason to think, should be vastly abridged. But grant it, for the sake of argument, in all its indefinite dimensions, and still the answer is, that a moment in a question of this kind is just as instructive as the lapse of a million of years. Time, while it witnesses change, does not create or of itself produce anything. It is rather a passive than an active agent. Time marks on its horoscope the effects of existing causes, but the causes themselves it neither fashions or eliminates. Geologists enter into minute calculations as to the annual decay of vegetables, and the transporting powers of water, the waste of forests and the uptearing of hurricanes. Grant them all to be correct, and the data in these respects to be unchallengeably sound, we again beg them to consider that the Mississippi bears on its bosom the earthy spoils of half a continent—that the Ganges mixes in its fabled flood the varied wreck of all the Himalaya,—and when all are duly borne onward by these and the mighty rivers elsewhere on the globe, that the arrangement of the mingled composite has yet to be effected—the clays, sands, coals, conglomerates, all in their serial superposition—the separation of the clean from the unclean—and where is the agency thus to dispose and to proportion? The deep says, it is not in me. The rivers show it is not in them. Are there any cosmical affinities in the things themselves to cause each to each, kind to kind, to take their respective places?

When we are told, that we know not what is going on in the depths of ocean, and other hollow places of the earth, our answer is two-fold. For first we reply, there were depths and hollows, lakes, estuaries, and seas, during all the intermediate succeeding epochs to the present age, and no true coal was produced: accumulation after accumulation of detrital alluvia followed, lapidified, and was distributed over extensive areas, and common to every region of the globe; but the real bituminous treasure has not been uniformly an accompaniment. A second answer is, that when and where vegetable matter, in any quantity, did accumulate, the result of the process was not coal. The lignites of the tertiary deposits, and many of the oolites, have been subjected to the first and second stages only in those changes which plants undergo in their transition into the bituminous combustible. Nature in these instances, if we may use the expression, has made the effort, but the same results have not followed; the process is incomplete, and the product is only in patches. If we are reminded of the great oolitic deposit of Richmond, in Virginia, re-examined and pronounced to be so by Sir C. Lyell, some may still say non-content, that the problem is not yet solved as to the true position of the coal there. Many anomalies in geognostic arrangements occur in that vast continent: many of the intermediate series up to the chalk are absent altogether, and the sandstones, discriminating the new from the old red, are not fully determined. Lignite, in considerable quantity, exists among the tertiary deposits of the Alps, and has recently been found in the north-west provinces of India, in the vicinity of Kalibag; but all partaking of the usual qualities—wood, only partially altered by inhumation, and imperfectly adapted for domestic purposes.

One overwhelming consideration with us, in the discussion of this question, is the position which man occupies, and the part he now plays on the theater of creation. The beasts and quadrupeds of the earth do not appear to have been formed so early as the carboniferous epoch. Had they existed at the period it is impossible to say what effects would have resulted from their graminivorous propensities in modifying the amount of the vegetable exuviæ. But man has appeared, modifying, changing, controlling everything—the earth and all its stores under his dominion—and all submissive to his will. He has little influence, indeed, over the more solid departments or structure of the globe—the form of its continents—the direction of its oceanic currents—the rise of islands and depression of land—the movements of the earthquake, and fiery torrents of the volcano; but over all its living products, especially its vegetable and terrestrial animal tribes, his influence is immense—increasingly incalculable. And, the geologist says, had this new denizen left the earth to itself, and nature to her own arrangements—were there no tilling, draining, and reaping—were the jungle and the wilderness to be still uninvaded—the marsh and the lagoon to welter in their dreary desolation—a vast coal deposit would be preparing in all the great lakes and seas of the globe. These postulates and conditions, however, can no longer be granted. Every day and every season they are all curtailed and limited in their influences. Man cuts down the forest, and applies it in its green, woody state to his own use.—The waste is reclaimed. The desert he makes his habitation; a place of beauty and civilization. The moral triumphs over the material, the spiritual over the earthy, and his charter-right is to subdue all things to himself. Thus the geologist cannot, if he would, forget or overlook the remarkable human epoch in which his own lot has been cast. As regards the future, there is a new element to which a due place must be assigned in his speculations; and all the great revolutions, and after-phases of our globe, he must henceforth read and interpret in the revealed destiny of his own race.

Finally, let it be assumed, in the argument for the geologists, that vast masses of vegetable matter are already stored up and duly arranged over the sea-bottom, that more is continually accumulating, and that there is heat enough under the earth’s crust to bituminize and indurate the whole. A new coal epoch is thus approaching, or rather, even now, we are living within its influences. But the question occurs, when completed, of what avail would it be to man, who would inevitably be swept off the earth in the elevation and breaking up of the strata from the depths beneath? Geology makes known the undoubted fact, that our planet has been subjected to many and most extensive changes before it was reduced to its present condition. These, from the beginning, have been all found subservient to the improvement and well-being of the human family. The next, upon a similar scale of magnitude, would inevitably prove the destruction of the race.

1. Sigillaria pachyderma. 2. Stigmaria ficoides. 3. Lepidodendron Sternbergii.

CHAPTER IX.
GEOLOGICAL STRUCTURE OF FIFESHIRE—DIVISIONS OF THE COAL-FIELD.

The general remarks on the coal deposit, in which we have been led to indulge in the two last chapters, may be verified by, as they all receive the most ample illustrations from, the admirable arrangement, position, and distribution of the metals in the counties of Fife, Clackmannan, Stirling, Lanark, and Renfrew, which are extensions of one great basin. Fifeshire alone contains an epitome of the system, divided as it is into numerous compartments, the encrinital limestone cropping out and marking their several boundaries. Indeed, the whole series of the carboniferous rocks are here laid open for examination on every hill-side, in the numerous ravines which intersect the district, and along the eastern and southern coast-lines. Approaching the coal-field from the north, a panoramic section at once fills the eye, and will rivet the attention, as, stepping from the strata of the antecedent epoch, you find, in immediate superposition as well as contrast of color, the multiplied and more diversified reliquiæ of the coal-measures.

The eruptive rocks will also be here studied to great advantage, where they have played no insignificant part in giving shape and outline to the landscape, and in laying open the inclosed minerals. It is impossible to convey any adequate idea, in mere description, of the marvelous display of plutonic action of which this peninsula has once been the theater: subterranean movements crushing and grinding into fragments the solid strata, parting and heaving them asunder, or crumpling into complicated folds the tougher and more unyielding beds, as if it had been some fabric of manufacture tossed and twisted by the wind. The bituminous breccia at Pettycur, Elie, Balcarras Den, and which appears again at the Rock and Spindle near St. Andrews, affords a remarkable instance of the action of the intrusive rocks in breaking, and transmuting into a composite paste, the series of beds constituting the coal-measures, in which every one of the strata has its representative in fragments, from the size of a garden pea to masses a foot in diameter or even upward. The storm lifts the ocean into lofty curling billows, leaving long narrow troughs and frightful yawning chasms beneath. Here, in like manner, and all over the surface, the crust has been broken up, and the minerals tossed about, or agitated like wreck upon the waves, and, upon subsiding, have been cast into the form of ridges, or broad tabular masses. The ridges, with their serrated outcrops, in the interior of the county, have been gradually rounded off and covered with soil; while, by the shore, they still present the effects of the violent commotions to which they have been subjected, exposed and laid bare by the action of the sea, upon the lower levels of the disrupted strata. The Ochils, Lammermuirs, and Pentlands, were already above the waters, calmly contemplating the troubled scene, as an inner circle of basalt and greenstone hills arose—the Lomonds, Largo Law, the Binn, and Binnarty, on the north; Stirling rock, Corstorphine hill, Arthur’s Seat, Berwick Law, and the Bass, on the south—which were severally lifted into view, to be stationed as so many sentinels on the outposts of the field.

The coal metals shared in the general elevation of the hills, where they are either folded round their bases, or are depending, drapery-wise, from their tops. Thus the members of the inferior carboniferous series are raised about eleven hundred feet along the Lomond ridge, encompassing the east and west cones, and training westward by Binnarty and the Cleish hills. Largo and Kellie Laws have each their coal basins, of workable minerals, stretched along their eminences, and dipping toward the Teasses and Ceres basins. On the low grounds which skirt them on the south, the metals dip rapidly into the Forth, and are collected in various hollows or independent bands by the shore. The intermediate coal-fields, which occupy the center of the basin, are regulated in their strike and inclination by the dykes and outbursts of trap by which the strata have been invaded. A limestone traverses the county at right angles from north to south, emerging at Ravenscrag, which forms a line of demarkation betwixt the number of the coal seams on its opposite sides. The Lochgellic, Cowdenbeath, and Dunfermline basins, on the west, average about twelve to fourteen workable coal-bands, while on the east of the limestone, the Dysart, Wemyss, Teasses, and Ceres basins run from twenty to thirty-three of various quality and thickness. The Clackmannan coal-field recovers in numerical proportion, where there are twenty-four seams of coal, from two inches to nine feet thick, and two great slips, which raise the metals successively 700 and 1230 feet, as they abut against the Ochil range. In the Elgin basin there are twenty-seven beds of coal, with a thickness of fifty-six feet.

Fifeshire thus owes its diversified shape and contour, and access to all its vast mineral treasures, to the early disturbances by which it has been so thoroughly dislocated and furrowed. Every district has a section, separate and independent, of its own. The ground you tread on is, every foot of it, a cabinet of wonders—literally a necropolis, a city of the dead. Go where you will, chronicles of the olden time are before and around you, while everywhere—

“and at your side

Rises a mountain-rock in rugged pride,

And in that rock are shapes of shells, and forms

Of creatures in old worlds.”

The cuttings of the Edinburgh and Perth Railway give excellent sections of the various minerals of the county, from the gray sandstone to the uppermost coverings of the coal-field. Entering Fifeshire from the west, your course lies deep among the detritus of the various members of the old red series already noticed. At the Newburgh Station, and under the cliffs of Clatchart, the gray sandstone and cornstone may be observed—the latter is regularly stratified; the former is embraced among the igneous rocks, broken, isolated, and inclined at every possible degree to the horizon. Clatchart Crag itself has been stirred to its foundations; the huge mass, reverberating now to the passage of other fires, rests on highly inclined beds of the gray sandstone; the black transverse dyke of basalt, a few hundred yards on the west, may be conjectured to have been the instrument of upheaval, as in fancy we can still discern in the half-raised, half-suspended position of the rock, the enormous pressure required for its elevation.

The Lomonds and Cults hills are conspicuous objects in the landscape. The line traverses for miles the yellow sandstone and overlaying grits which form their base. Greenstone and augitic trap in both ranges cap the summits, bursting through the coal metals, and elevating the various beds of limestone. The encrinital limestone sweeps round the peaks of the Lomonds, filling up the intermediate plateau, in some places bare of herbage or any covering of soil, and the fossils are lying exposed on the surface fresh as when washed by the waves, about eleven hundred feet above their ancient sea-bottom. A vein of galena occurs on the south side of the hill, intersecting the limestone at right angles to the plain of stratification, and is described in the notices of the period of its discovery as rich in silver ore. But it has no great claim, we believe, to be regarded as argentiferous. Two similar veins traverse the county, one already noticed in Dura Den, and the other in the parish of Inverkeithing, situated among the same series of rocks, and having the same general line of bearing from nearly north-east by south-west. The lead ore in all of them is partly massive, and partly in regular hexahedral crystals. Lead, copper, cobalt, and silver are likewise found in the Ochil range, but in no great quantities, in the culminating heights betwixt Dollar, Bencleugh, and Dalmyat.

On approaching the river Leven at Markinch, the out-crop of the central coal-basin comes to the surface. After crossing the viaduct the line lies deep among the metals—a repetition of faults, upheavals, and depressions, where in succession the edges of the same beds are several times passed over. The dip is various, the strike generally to the south-east, and under the sea at Dysart the metals are wrought at the depth of several hundred feet.

The igneous rocks along the coast will not fail to call forth surprise and admiration, unrivaled as they probably are in the number of alternations with the deposits of the carboniferous series, and all the interesting phenomena which accompany their intrusion. No description, indeed, can do justice to the interlacings and alternations presented of the two classes of rocks, so different in their origin, as those of the traps and coal-measures; where, through the agency of the former, the latter series are bent, twisted, re-united, altered, and lying at every angle betwixt the horizontal and perpendicular. Nearing Kirkaldy the coal is split up, and the fused matter injected between the layers, converting them into cinder. Within the distance of a mile, from Seaforth to Kinghorn, there are from forty to fifty alternations of the igneous and sedimentary rocks; and again, on the west, toward Pittycur, there is a recurrence of as many, with examples of the jointed columnar basalt reposing on sandstones rendered quartzose, or converted into chert, and on shales baked into brick. The outburst at the Burntisland terminus, in three parallel ridges, throws up the strata, inclining them toward the north, whence trending round the town they dip under the Binn-hill. Orrock-hill, lying immediately to the north-east of Binn-hill, furnishes a beautiful example of jointed basalt: the entire rock, three hundred feet high, and nearly a mile long, by half-a-mile in breadth, is composed of regularly constructed columns, which divide into concretionary masses from one to three feet in length, and presenting generally the pentagonal or hexagonal form. The columns are grouped into distinct clusters, which, inclining at various angles, impart to the exposed face of the rock a pleasing picturesque effect. The erosive action of water, or swell of the ocean tide, is all that is required here to shape another Staffa—“that wondrous dome”—out of these magnificent materials.

A fresh-water, or rather perhaps an estuary, limestone is an object of considerable geological interest in this locality, mixed up and altered in many places by the igneous matter. The best sections occur a little back from Pittycur harbor, and on the western slope of Binn-hill, where it is extensively quarried. Scales of fishes and other ichthyolites are very abundant: also innumerable microscopic shells, belonging to the order of entomostraca and the genus cypris. Several species of palæoniscus have been found in good preservation, namely, P. ariolatis, P. ornatissimus, and P. Robisoni. The Pygopteris Jamesoni and specimens of the Eurynotus and Crenatis have likewise been detected in the deposit. Vegetable remains are very plentiful, especially of the fern tribe and the lycopodiums: the impressions of the sphenopteris, of which there are several species, are extremely numerous, fresh, and beautiful. This limestone is of a dull, earthy aspect, acquired obviously from the bituminous matter diffused through the mass; not crystalline, though very compact in texture, and possessed of great hardness. Wardie beach, on the opposite shore, displays a bed having many points of resemblance, which abounds in nodular masses, inclosing coprolites and fishes; and inland, the celebrated Burdiehouse limestone is an extension of the Fifeshire deposit.

Thus varied and important is this small peninsula, a speck on the face of the globe, and affording so much room for speculation and detail. Inclosed between the estuaries of the Tay and Forth are to be found some of the most legible and remarkable chronicles of our planet’s history. Fifeshire has been stirred and upheaved all over, abounding in all the life-moving and plutonic energies of the carboniferous age. The vegetable and animal kingdoms supply a vast proportion of the materials of the sedimentary rocks, while the fires of the interior have mainly contributed to the production of the rest. Shall we look across the waters, and replace them, in imagination, by the former continuity of land, when the center of the coal-basin was raised above them, and their numerous islets were high and dry upon the surface? Certain it is, that the erupted matter so abundantly scattered along the shores and piled up in such masses landward, would leave room for subsidence, while the outgoing of the deposits on both sides shows such an affinity in quality and strike as to demonstrate an ancient union and geological connection.