In the erupted lavas, those substances which are subject to calcine and vitrify in our fires, suffer similar changes, when delivered from a compression which had rendered them fixed, though in an extremely heated state. Thus, a lava in which there is much calcareous spar, when it comes to be exposed to the atmosphere, or delivered from the compressing force of its confinement, effervesces by the explosion of its fixed air; the calcareous earth, at the same time, vitrifies with the other substances. Hence such violent ebullition in volcanos, and hence the emission of so much pumice-stone and ashes, which are of the same nature.

In the body of our whin-stone, on the contrary, there is no mark of calcination or vitrification. We frequently find in it much calcareous spar, or the terra calcarea aerata, which had been in a melted state by heat, and had been crystallized by congelation into a sparry form. Such is the lapis amygdaloides, and many of our whin-stone rocks, which contain pebbles crystallized and variously figured, both calcareous, siliceous, and of a mixture in which both these substances form distinct parts. The specimens of this kind, which I have from the whin-stone or porphyry rock of the Calton-hill, exhibit every species of mineral operation, in forming jasper, figured agate, and marble; and they demonstrate, that this had been performed by heat or fusion.

I do not mean to say, that this demonstration is direct; it is conditional, and proceeds upon the supposition, that the basaltic or porphyry rock, in which those specimens are found, is a body which had been in a melted state. Now, this is a supposition for which I have abundance of evidence, were it required; but naturalists are now sufficiently disposed to admit that proposition; they even draw conclusions from this fact, which, I think, they are not sufficiently warranted in doing; that is, from this appearance, they infer the former existence of volcanos in those places. For my part, though I have made the most strict examination, I never saw any vestige of such an event. That there are, in other countries, evident marks of volcanos which have been long extinguished, is unquestionably true; but naturalists, imagining that there are no other marks of subterraneous fire and fusion, except in the production of a lava, attribute to a volcano, as a cause, these effects, which only indicate the exertion of that power which might have been the cause of a volcano.

If the theory now given be just, a rock of marble is no less a mark of subterraneous fire and fusion, than that of the basaltes; and the flowing of basaltic streams among strata broken and displaced, affords the most satisfactory evidence of those operations by which the body of our land had been elevated above the surface of the sea; but it gives no proof that the eruptive force of mineral vapours had been discharged in a burning mountain. Now, this discharge is essential in the proper idea of a volcano.

Besides this internal mark of an unerupted lava in the substance of the stone or body of the flowing mass, there are others which belong to it in common with all other mineral strata, consolidated by subterraneous fire, and changed from the place of their original formation; this is, the being broken and dislocated, and having veins of foreign matter formed in their separations and contractions.

If these are mineral operations, proper to the lower regions of the earth, and exerted upon bodies under immense compression, such things will be sometimes found in the unerupted lavas, as well as in the contiguous bodies with which they are associated. If, on the contrary, these are operations proper to the surface of the earth, where the dissolving power of water and air take place, and where certain stalactical and ferruginous concretions are produced by these means; then, in erupted lavas, we should find mineral concretions, which concretions should be denied to bodies which had been consolidated at the bottom of the sea; that is to say, where, without the operation of subterraneous fire, no changes of that kind could have taken place, as has already been observed. But in the unerupted species of lava, that is to say, in our whin-stone, every species of mineral appearance is occasionally to be found. Let those who have the opportunity to examine, say, what arc to be found in proper lavas, that is, those of the erupted kind. Sir William Hamilton informed me, when I showed him those mineral veins and spars in our whin-stone, that he had never observed the like, in lavas We have now formed some conclusions with regard to the nature and production of those parts of the land of this globe which we have had the means of examining perfectly; but; from the accounts of travellers, and from, the specimens which are brought to us from distant parts, we have reason to believe, that all the rest of the earth is of the same nature with that which has been now considered. The great masses of the earth are the same every where; and all the different species of earths, of rocks or stone, which have as yet appeared, are to be found in the little space of this our island.

It is true, that there are peculiar productions in the mineral kingdom which are rare, as being found only in few places; but these things are merely accidental in relation to the land, for they belong in property to those parts of the mineral region which we never see. Such are, the diamond of the east, the platina of the west, and the tin of Cornwall, Germany, and Sumatra. Gold and silver, though found in many countries, do not appear to be immediately necessary in the production of a habitable country. Iron, again, is universal in the operations of the globe, and is found often in that profusion which equals its utility. Between these two extremes, we find all other minerals, that is to say, here and there in moderate quantity, and apparently in some proportion to their use. But all these substances are to be considered as the vapours of the mineral regions, condensed occasionally in the crevices of the land; and it is only the rocks and strata (in which those mineral veins are found) that are now examined with regard to their original composition, at the bottom of the sea, as well as to that, operation by which those bodies had been indurated in their substance, and elevated from the place in which they had been formed.

Thus, we have sufficient reason to believe, that, in knowing the construction of the land in Europe, we know the constitution of the land in every part of the globe. Therefore, we may proceed to form general conclusions, from the knowledge of the mineral region, thus acquired in studying those parts which are seen.

Having thus found, first, That the consolidated and indurated masses of our strata had suffered the effects of violent heat and fusion; 2dly, That those strata, which had been formed in a regular manner at the bottom of the sea, have been violently bended, broken, and removed from their original place and situation; and, lastly, Having now found the most indubitable proof, that the melting, breaking, and removing power of subterraneous fire, has been actually exerted upon this land which we examine, we cannot hesitate in ascribing these operations as a cause to those effects which are exposed to our view. Now, these may be considered as consisting in the solid state and present situation of those stratified bodies, originally formed by subsidence in the ocean; appearances which cannot, in reason, be ascribed to any other cause, and which, upon this principle, are perfectly explained.

It is not meant to specify every particular in the means employed by nature for the elevation of our land. It is sufficient to have shown, that there is, in nature, means employed for the consolidating of strata, formed originally of loose and incoherent materials; and that those same means have also been employed in changing the place and situation of those strata. But how describe an operation which man cannot have any opportunity of perceiving? Or how imagine that, for which, perhaps, there are not proper data to be found? We only know, that the land is raised by a power which has for principle subterraneous heat; but, how that land is preserved in its elevated station, is a subject in which we have not even the means to form conjecture; at least, we ought to be cautious how we indulge conjecture in a subject where no means occur for trying that which is but supposition.

We now proceed, from the facts which have been properly established, to reason with regard to the duration of this globe, or the general view of its operations, as a living world, maintaining plants and animals.

SECTION IV.

System of Decay and Renovation observed in the Earth.

Philosophers observing an apparent disorder and confusion in the solid parts of this globe, have been led to conclude, that there formerly existed a more regular and uniform state, in the constitution of this earth; that there had happened some destructive change; and that the original structure of the earth had been broken and disturbed by some violent operation, whether natural, or from a super-natural cause. Now, all these appearances, from which conclusions of this kind have been formed, find the most perfect explanation in the theory which we have been endeavouring to establish; for they are the facts from whence we have reasoned, in discovering the nature and constitution of this earth: Therefore, there is no occasion for having recourse to any unnatural supposition of evil, to any destructive accident in nature, or to the agency of any preternatural cause, in explaining that which actually appears.

It is necessary for a living or inhabited world, that this should consist of land and water. It is also necessary, that the land should be solid and stable, refilling, with great power, the violent efforts of the ocean; and, at the same time, that this solid land should be resolved by the influence of the sun and atmosphere, so as to decay, and thus become a soil for vegetation. But these general intentions are perfectly fulfilled in the constitution of our earth, which has been now investigated. This great body being formed of different mixed masses, having various degrees of hardness and solubility, proper soil for plants is supplied from the gradual resolution of the solid parts; fertility in those soils arises from the mixture of different elementary substances; and stability is procured to that vegetable world, by the induration of certain bodies, those rocks and stones, which protect the softer masses of clay and soil.

In this manner, also, will easily be explained those natural appearances which diversify the surface of the earth for the use of plants and animals, and those objects which beautify the face of nature for the contemplation of mankind. Such are, the distinctions of mountains and valleys, of lakes and rivers, of dry barren deserts and rich watered plains, of rocks which stand apparently unimpaired by the lapse of time, and sands which fluctuate with the winds and tides. All these are the effects of steady causes; each of these has its proper purpose in the system of the earth; and in that system is contained another, which is that of living growing bodies, and of animated beings.

But, besides this, man, the intellectual being, has, in this subject of the mineral kingdom, the means of gratifying the desire of knowledge, a faculty by which he is distinguished from the animal, and by which he improves his mind in knowing causes. Man is not satisfied, like the brute, in seeing things which are; he seeks to know how things have been, and what they are to be. It is with pleasure that he observes order and regularity in the works of nature, instead of being disgusted with disorder and confusion; and he is made happy from the appearance of wisdom and benevolence in the design, instead of being left to suspect in the Author of nature, any of that imperfection which he finds in himself.

Let us now take a view of that system of mineral economy, in which may be perceived every mark of order and design, of provident wisdom and benevolence.

We have been endeavouring to prove, that all the continents and islands of this globe had been raised above the surface of the ocean; we have also aimed at pointing out the cause of this translation of matter, as well as of the general solidity of that which is raised to our view; but however this theory shall be received, no person of observation can entertain a doubt, that all, or almost all we see of this earth, had been originally formed at the bottom of the sea. We have now another object in our view; this is to investigate the operations of the globe, at the time that the foundation of this land was laying in the waters of the ocean, and to trace the existence and the nature of things, before the present land appeared above the surface of the waters. We should thus acquire some knowledge of the system according to which this world is ruled, both in its preservation and production; and we might be thus enabled to judge, how far the mineral system of the world shall appear to be contrived with all the wisdom, which is so manifest in what are termed the animal and vegetable kingdoms.

It must not be imagined that this undertaking is a thing unreasonable in its nature; or that it is a work necessarily beset with any unsurmountable difficulty; for, however imperfectly we may fulfill this end proposed, yet, so far as it is to natural causes that are to be ascribed the operations of former time, and so far as, from the present state of things, or knowledge of natural history, we have it in our power to reason from effect to cause, there are, in the constitution of the world, which we now examine, certain means to read the annals of a former earth.

The object of inquiry being the operations of the globe, during the time that the present earth was forming at the bottom of the sea, we are now to take a very general view of nature, without descending into those particulars which so often occupy the speculations of naturalists, about the present state of things. We are not at present to enter into any discussion with regard to what are the primary and secondary mountains of the earth; we are not to consider what is the first, and what the last, in those things which now are seen; whatever is most ancient in the strata which we now examine, is supposed to be collecting at the bottom of the sea, during the period concerning which we are now to inquire.

We have already considered those operations which had been necessary in forming our solid land, a body consisting of materials originally deposited at the bottom of the ocean; we are now to investigate the source from whence had come all those materials, from the collection of which the present land is formed; and from knowing the state in which those materials had existed, previously to their entering the composition of our strata, we shall learn something concerning the natural history of this world, while the present earth was forming in the sea.

We have already observed, that all the strata of the earth are composed either from the calcareous relicts of sea animals, or from the collection of such materials as we find upon our shores. At a gross computation, there may perhaps be a fourth part of our solid land, which is composed from the matter that had belonged to those animals. Now, what a multitude of living creatures, what a quantity of animal economy must have been required for producing a body of calcareous matter which is interspersed throughout all the land of the globe, and which certainly forms a very considerable part of that mass! Therefore, in knowing how those animals had lived, or with what they had been fed, we shall have learned a most interesting part of the natural history of this earth; a part which it is necessary to have ascertained, in order to see the former operations of the globe, while preparing the materials of the present land. But, before entering upon this subject, let us examine the other materials of which our land is formed.

Gravel forms a part of those materials which compose our solid land; but gravel is no other than a collection of the fragments of solid stones worn round, or having their angular form destroyed by agitation in water, and the attrition upon each other, or upon similar hard bodies. Consequently, in finding masses of gravel in the composition of our land, we must conclude, that there had existed a former land, on which there had been transacted certain operations of wind and water, similar to those which are natural to the globe at present, and by which new gravel is continually prepared, as well as old gravel consumed or diminished by attrition upon our shores.

Sand is the material which enters, perhaps in greatest quantity, the composition of our land. But sand, in general, is no other than small fragments of hard and solid bodies, worn or rounded more or less by attrition; consequently, the same natural history of the earth, which is investigated from the masses of gravel, is also applicable to those masses of sand which we find forming so large a portion of our present land throughout all the earth[16].

[Note 16: Sand is a term that denotes no particular substance; although by it is commonly meant a siliceous substance, as being by far the most prevalent. Sand is one of the modifications, of size and shape, in a hard body or solid substance, which may be infinitely diversified. The next modification to be distinguished in mineral bodies is that of gravel; and this differs in no respect from sand, except in point of size. Next after gravel, in the order of ascent, come stones; and these bear nearly the same relation to gravel as gravel does to sand. Now, by stones is to be understood the fragments of rocks or solid mineral bodies; and there is a perfect gradation from those stones to sand. I have already endeavoured to explain the formation of those stony substances; and now I am treating of a certain system of circulation, which is to be found among minerals.

M. de Luc censures me for not giving the origin of sand, of which I form the strata of the earth. He seems to have misunderstood my treatise. I do not pretend, as he does in his theory, to describe the beginning of things; I take things such as I find them at present, and from these I reason with regard to that which must have been. When, from a thing which is well known, we explain another which is less so, we then investigate nature; but when we imagine things without a pattern or example in nature, then, instead of natural history, we write only fable.

M. de Luc, in the letter already mentioned, says, "that sand may be, and I think it is, a substance which has formed strata by precipitation in a liquid." This is but an opinion, which may be either true or false. If it be true, it is an operation of the mineral kingdom of which I am ignorant. In all the sand which I have ever examined, I have never seen any that might not be referred to the species of mineral substance from which it had been formed. When this author shall have given us any kind of information with regard to the production of sand by precipitation in a liquid, it will then be time enough to think of forming the strata of the earth with that sand.]

Clay is now to be considered as the last of those materials of which our strata are composed; but, in order to understand the nature of this ingredient, something must be premised.

Clay is a mixture of different earths or hard substances, in an impalpable state. Those substances are chiefly the siliceous and aluminous earths. Other earths are occasionally mixed in clays, or perhaps always to be found in some small portion. But this does not affect the general character of clay; it only forms a special variety in the subject. A sensible or considerable portion of calcareous earth, in the composition of clay, constitutes a marl, and a sufficient admixture of sand, a loam.

An indefinite variety of those compositions of clay form a large portion of the present strata, all indurated and consolidated in various degrees; but this great quantity of siliceous, argillaceous, and other compound substances, in form of earth or impalpable sediment, corresponds perfectly with that quantity of those same substances which must have been prepared in the formation of so much gravel and sand, by the attrition of those bodies in the moving waters.

Therefore, from the consideration of those materials which compose the present land, we have reason to conclude, that, during the time this land was forming, by the collection of its materials at the bottom of the sea, there had been a former land containing materials similar to those which we find at present in examining the earth. We may also conclude, that there had been operations similar to those which we now find natural to the globe, and necessarily exerted in the actual formation of gravel, sand, and clay. But what we have now chiefly in view to illustrate is this, that there had then been in the ocean a system of animated beings, which propagated their species, and which have thus continued their several races to this day.

In order to be convinced of that truth, we have but to examine the strata of our earth, in which we find the remains of animals. In this examination, we not only discover every genus of animal which at present exists in the sea, but probably every species, and perhaps some species with which at present we are not acquainted. There are, indeed, varieties in those species, compared with the present animals which we examine, but no greater varieties than may perhaps be found among the same species in the different quarters of the globe. Therefore, the system of animal life, which had been maintained in the ancient sea, had not been different from that which now subsists, and of which it belongs to naturalists to know the history.

It is the nature of animal life to be ultimately supported from matter of vegetable production. Inflammable matter may be considered as the pabulum of life. This is prepared in the bodies of living plants, particularly in their leaves exposed to the sun and light. This inflammable matter, on the contrary, is consumed in animal bodies, where it produces heat or light, or both. Therefore, however animal matter, or the pabulum of life, may circulate through a series of digesting powers, it is constantly impaired or diminishing in the course of this economy, and, without the productive power of plants, it would finally be extinguished.[17]

[Note 17: See Dissertations on different subjects of Natural Philosophy, part II.]

The animals of the former world must have been sustained during indefinite successions of ages. The mean quantity of animal matter, therefore, must have been preserved by vegetable production, and the natural waste of inflammable substance repaired with continual addition; that is to say, the quantity of inflammable matter necessary to the animal consumption, must have been provided by means of vegetation. Hence we must conclude, that there had been a world of plants, as well as an ocean replenished with living animals.

We are now, in reasoning from principles, come to a point decisive of the question, and which will either confirm the theory, if it be just, or confute our reasoning, if we have erred. Let us, therefore, open the book of Nature, and read in her records, if there had been a world bearing plants, at the time when this present world was forming at the bottom of the sea.

Here the cabinets of the curious are to be examined; but here some caution is required, in order to distinguish things perfectly different, which sometimes are confounded.

Fossil wood, to naturalists in general, is wood dug up from under ground, without inquiring whether this had been the production of the present earth, or that which had preceded it in the circulation of land and water. The question is important, and the solution of it is, in general, easy. The vegetable productions of the present earth, however deep they may be found buried beneath its surface, and however ancient they may appear, compared with the records of our known times, are new, compared with the solid land on which they grew; and they are only covered with the produce of a vegetable soil, or the alluvion of the present land on which we dwell, and on which they had grown. But the fossil bodies which form the present subject of inquiry, belonged to former land, and are found only in the sea-born strata of our present earth. It is to these alone that we appeal, in order to prove the certainty of former events.

Mineralised wood, therefore, is the object now inquired after; that wood which had been lodged in the bottom of the sea, and there composed part of a stratum, which hitherto we have considered as only formed of the materials proper to the ocean. Now, what a profusion of this species of fossil wood is to be found in the cabinets of collectors, and even in the hands of lapidaries, and such artificers of polished stones! In some places, it would seem to be as common as the agate.

I shall only mention a specimen in my own collection. It is wood petrified with calcareous earth, and mineralised with pyrites. This specimen of wood contains in itself, even without the stratum of stone in which it is embedded, the most perfect record of its genealogy. It had been eaten or perforated by those sea worms which destroy the bottoms of our ships. There is the clearest evidence of this truth. Therefore, this wood had grown upon land which flood above the level of sea, while the present land was only forming at the bottom of the ocean.

Wood is the most substantial part of plants, as shells are the more permanent part of marine animals. It is not, however, the woody part alone of the ancient vegetable world that is transmitted to us in the record of our mineral pages. We have the type of many species of foliage, and even of the most delicate flower; for, in this way, naturalists have determined, according to the Linnaean system, the species, or at least the genus, of the plant. Thus, the existence of a vegetable system at the period now in contemplation, so far from being doubtful, is a matter of physical demonstration.

The profusion of this vegetable matter, delivered into the ocean, which then generated land, is also evidenced in the amazing quantities of mineral coal which is to be found in perhaps every region of the earth.

Nothing can be more certain, than that all the coaly or bituminous strata have had their origin from the substance of vegetable bodies that grew upon the land. Those strata, tho', in general, perfectly consolidated, often separate horizontally in certain places; and there we find the fibrous or vascular structure of the vegetable bodies. Consequently, there is no doubt of fossil coal being a substance of vegetable production, however animal substances also may have contributed in forming this collection of oleaginous or inflammable matter.

Having thus ascertained the state of a former earth, in which plants and animals had lived, as well as the gradual production of the present earth, composed from the materials of a former world, it must be evident, that here are two operations which are necessarily consecutive. The formation of the present earth necessarily involves the destruction of continents in the ancient world; and, by pursuing in our mind the natural operations of a former earth, we clearly see the origin of that land, by the fertility of which, we, and all the animated bodies of the sea, are fed. It is in like manner, that, contemplating the present operations of the globe, we may perceive the actual existence of those productive causes, which are now laying the foundation of land in the unfathomable regions of the sea, and which will, in time, give birth to future continents.

But though, in generalising the operations of nature, we have arrived at those great events, which, at first sight, may fill the mind with wonder and with doubt, we are not to suppose, that there is any violent exertion of power, such as is required in order to produce a great event in little time; in nature, we find no deficiency in respect of time, nor any limitation with regard to power. But time is not made to flow in vain; nor does there ever appear the exertion of superfluous power, or the manifestation of design, not calculated in wisdom to effect some general end.

The events now under consideration may be examined with a view to see this truth; for it may be inquired, Why destroy one continent in order to erect another? The answer is plain; Nature does not destroy a continent from having wearied of a subject which had given pleasure, or changed her purpose, whether for a better or a worse; neither does she erect a continent of land among the clouds, to show her power, or to amaze the vulgar man; Nature has contrived the productions of vegetable bodies, and the sustenance of animal life, to depend upon the gradual but sure destruction of a continent; that is to say, these two operations necessarily go hand in hand. But with such wisdom has nature ordered things in the economy of this world, that the destruction of one continent is not brought about without the renovation of the earth in the production of another; and the animal and vegetable bodies, for which the world above the surface of the sea is leveled with its bottom, are among the means employed in those operations, as well as the sustenance of those living beings is the proper end in view.

Thus, in understanding the proper constitution of the present earth, we are led to know the source from whence had come all the materials which nature had employed in the construction of the world which appears; a world contrived in consummate wisdom for the growth and habitation of a great diversity of plants and animals; and a world peculiarly adapted to the purposes of man, who inhabits all its climates, who measures its extent, and determines its productions at his pleasure.

The whole of a great object or event fills us with wonder and astonishment, when all the particulars, in the succession of which the whole had been produced, may be considered without the least emotion. When, for example, we behold the pyramids of Egypt, our mind is agitated with a crowd of ideas that highly entertains the person who understands the subject; but the carrying a heavy stone up to the top of a hill or mountain would give that person little pleasure or concern. We wonder at the whole operation of the pyramid, but not at any one particular part.

The raising up of a continent of land from the bottom of the sea, is an idea that is too great to be conceived easily in all the parts of its operations, many of which are perhaps unknown to us; and, without being properly understood, so great an idea may appear like a thing that is imaginary. In like manner, the co-relative, or corresponding operation, the destruction of the land, is an idea that does not easily enter into the mind of man in its totality, although he is daily witness to part of the operation. We never see a river in a flood, but we must acknowledge the carrying away of part of our land, to be sunk at the bottom of the sea; we never see a storm upon the coast, but we are informed of a hostile attack of the sea upon our country; attacks which must, in time, wear away the bulwarks of our soil, and sap the foundations of our dwellings. Thus, great things are not understood without the analysing of many operations, and the combination of time with many events happening in succession.

Let us now consider what is to be the subject of examination, and where it is that we are to observe those operations which must determine either the stability or the instability of this land on which we live.

Our land has two extremities; the tops of the mountains, on the one hand, and the sea-shores, on the other: It is the intermediate space between these two, that forms the habitation of plants and animals. While there is a sea-shore and a higher ground there is that which is required in the system of the world: Take these away, and there would remain an aqueous globe, in which the world would perish. But, in the natural operations of the world, the land is perishing continually; and this is that which now we want to understand.

Upon the one extremity of our land, there is no increase, or there is no accession of any mineral substance. That place is the mountain-top, on which nothing is observed but continual decay. The fragments of the mountain are removed in a gradual succession from the highest station to the lowest. Being arrived at the shore, and having entered the dominion of the waves, in which they find perpetual agitation, these hard fragments, which had eluded the resolving powers natural to the surface of the earth, are incapable of resisting the powers here employed for the destruction of the land. By the attrition of one hard body upon another, the moving stones and rocky shore, are mutually impaired. And that solid mass, which of itself had potential liability against the violence of the waves, affords the instruments of its own destruction, and thus gives occasion to its actual instability.

In order to understand the system of the heavens, it is necessary to connect together periods of measured time, and the distinguished places of revolving bodies. It is thus that system may be observed, or wisdom, in the proper adapting of powers to an intention. In like manner, we cannot understand the system of the globe, without seeing that progress of things which is brought about in time, thus measuring the natural operations of the earth with those of the heavens. This is properly the business of the present undertaking.

Our object is to know the time which had elapsed since the foundation of the present continent had been laid at the bottom of the ocean, to the present moment in which we speculate on these operations. The space is long; the data for the calculations are, perhaps, deficient: No matter; so far as we know our error, or the deficiency in our operation, we proceed in science, and shall conclude in reason. It is not given to man to know what things are truly in themselves, but only what those things are in his thought. We seek not to know the precise measure of any thing; we only understand the limits of a thing, in knowing what it is not, either on the one side or the other.

We are investigating the age of the present earth, from the beginning of that body which was in the bottom of the sea, to the perfection of its nature, which we consider as in the moment of our existence; and we have necessarily another aera, which is collateral, or correspondent, in the progress of those natural events. This is the time required, in the natural operations of this globe, for the destruction of a former earth; an earth equally perfect with the present and an earth equally productive of growing plants and living animals. Now, it must appear, that, if we had a measure for the one of those corresponding operations, we would have an equal knowledge of the other.

The formation of a future earth being in the bottom of the ocean, at depths unfathomable to man, and in regions far beyond the reach of his observation, here is a part of the process which cannot be taken as a principle in forming an estimate of the whole. But, in the destruction of the present earth, we have a process that is performed within the limits of our observation; therefore, in knowing the measure of this operation, we shall find the means of calculating what had passed on a former occasion, as well as what will happen in the composition of a future earth. Let us, therefore, now attempt to make this estimate of time and labour.

The highest mountain may be levelled with the plain from whence it springs, without the loss of real territory in the land; but when the ocean makes encroachment on the basis of our earth, the mountain, unsupported, tumbles with its weight; and with the accession of hard bodies, moveable with the agitation of the waves, gives to the sea the power of undermining farther and farther into the solid basis of our land. This is the operation which is to be measured; this is the mean proportional by which we are to estimate the age of worlds that have terminated, and the duration of those that are but beginning.

But how shall we measure the decrease of our land? Every revolution of the globe wears away some part of some rock upon some coast; but the quantity of that decrease, in that measured time, is not a measurable thing. Instead of a revolution of the globe, let us take an age. The age of man does no more in this estimate than a single year. He sees, that the natural course of things is to wear away the coast, with the attrition of the sand and stones upon the shore; but he cannot find a measure for this quantity which shall correspond to time, in order to form an estimate of the rate of this decrease.

But man is not confined to what he sees; he has the experience of former men. Let us then go to the Romans and the Greeks in search of a measure of our coasts, which we may compare with the present state of things. Here, again, we are disappointed; their descriptions of the shores of Greece and of Italy, and their works upon the coast, either give no measure of a decrease, or are not accurate enough for such a purpose.

It is in vain to attempt to measure a quantity which escapes our notice, and which history cannot ascertain; and we might just as well attempt to measure the distance of the stars without a parallax, as to calculate the destruction of the solid land without a measure corresponding to the whole.

The description which Polybius has given of the Pontus Euxinus, with the two opposite Bosphori, the Meotis, the Propontis, and the Port of Byzantium, are as applicable to the present state of things as they were at the writing of that history. The filling up of the bed of the Meotis, an event which, to Polybius, appeared not far off, must also be considered as removed to a very distant period, though the causes still continue to operate as before.

But there is a thing in which history and the present state of things do not agree. It is upon the coast of Spain, where Polybius says there was an island in the mouth of the harbour of New Carthage. At present, in place of the island, there is only a rock under the surface of the water. It must be evident, however, that the loss of this small island affords no proper ground of calculation for the measure or rate of wasting which could correspond to the coast in general; as neither the quantity of what is now lost had been measured, nor its quality ascertained.

Let us examine places much more exposed to the fury of the waves and currents than the coast of Carthagena, the narrow fretum, for example, between Italy and Sicily. It does not appear, that this passage is sensibly wider than when the Romans first had known it. The Isthmus of Corinth is also apparently the same at present as it had been two or three thousand years ago. Scilla and Charibdis remain now, as they had been in ancient times, rocks hazardous for coasting vessels which had to pass that strait.

It is not meant by this to say, these rocks have not been wasted by the sea, and worn by the attrition of moving bodies, during that space of time; were this true, and that those rocks, the bulwarks of the land upon those coasts, had not been at all impaired from that period, they might remain for ever, and thus the system of interchanging the place of sea and land upon this globe might be frustrated. It is only meant to affirm, that the quantity which those rocks, or that coast, have diminished from the period of our history, has either been too small a thing for human observation, or, which is more probable, that no accurate measurement of the subject, by which this quantity of decrease might have been ascertained, had been taken and recorded. It must be also evident, that a very small operation of an earthquake would be sufficient to render every means of information, in this manner of mensuration, unsatisfactory or precarious.

Pliny says Italy was distant from Sicily a mile and a half; but we cannot suppose that this measure was taken any otherwise than by computation, and such a measure is but little calculated to afford us the just means of a comparison with the present distance. He also says, indeed, that Sicily had been once joined with Italy. His words are: "Quondam Brutio agro cohaerens, mox interfuso mari avulsa.[18]" But all that we can conclude from this history of Pliny is, that, in all times, to people considering the appearances of those two approached coasts, it had seemed probable, that the sea formed a passage between the two countries which had been once united; in like manner as is still more immediately perceived, in that smaller disjunction which is made between the island of Anglesey and the continent of Wales.

[Note 18: Lib. 3. cap. 8.]

The port of Syracuse, with the island which forms the greater and lesser, and the fountain of Arethusa, the water of which the ancients divided from the sea with a wall, do not seem to be altered. From Sicily to the coast of Egypt, there is an uninterrupted course of sea for a thousand miles; consequently, the wind, in such a stretch of sea, should bring powerful waves against those coasts: But, on this coast of Egypt, we find the rock on which was formerly built the famous tower of Pharos; and also, at the eastern extremity of the port Eunoste, the sea-bath, cut in the solid rock upon the shore. Both those rocks, buffeted immediately with the waves of the Mediterranean sea, are, to all appearance, the same at this day as they were in ancient times.[19]

[Note 19: Lettres sur l'Egypte, M. Savary.]

Many other such proofs will certainly occur, where the different parts of those coasts are examined by people of observation and intelligence. But it is enough for our present purpose, that this decrease of the coasts in general has not been observed; and that it is as generally thought, that the land is gaining upon the sea, as that the sea is gaining upon the land.

To sum up the argument, we are certain, that all the coasts of the present continents are wasted by the sea, and constantly wearing away upon the whole; but this operation is so extremely slow, that we cannot find a measure of the quantity in order to form an estimate: Therefore, the present continents of the earth, which we consider as in a state of perfection, would, in the natural operations of the globe, require a time indefinite for their destruction.

But, in order to produce the present continents, the destruction of a former vegetable world was necessary; consequently, the production of our present continents must have required a time which is indefinite. In like manner, if the former continents were of the same nature as the present, it must have required another space of time, which also is indefinite, before they had come to their perfection as a vegetable world.

We have been representing the system of this earth as proceeding with a certain regularity, which is not perhaps in nature, but which is necessary for our clear conception of the system of nature. The system of nature is certainly in rule, although we may not know every circumstance of its regulation. We are under a necessity, therefore, of making regular suppositions, in order to come at certain conclusions which may be compared with the present state of things.

It is not necessary that the present land should be worn away and wasted, exactly in proportion as new land shall appear; or, conversely, that an equal proportion of new land should always be produced as the old is made to disappear. It is only required, that at all times, there should be a just proportion of land and water upon the surface of the globe, for the purpose of a habitable world.

Neither is it required in the actual system of this earth, that every part of the land should be dissolved in its structure, and worn away by attrition, so as to be floated in the sea. Parts of the land may often sink in a body below the level of the sea, and parts again may be restored, without waiting for the general circulation of land and water, which proceeds with all the certainty of nature, but which advances with an imperceptible progression. Many of such apparent irregularities may appear without the least infringement on the general system. That system is comprehended in the preparation of future land at the bottom of the ocean, from those materials which the dissolution and attrition of the present land may have provided, and from those which the natural operations of the sea afford.

In thus accomplishing a certain end, we are not to limit nature with the uniformity of an equable progression, although it be necessary in our computations to proceed upon equalities. Thus also, in the use of means, we are not to prescribe to nature those alone which we think suitable for the purpose, in our narrow view. It is our business to learn of nature (that is by observation) the ways and means, which in her wisdom are adopted; and we are to imagine these only in order to find means for further information, and to increase our knowledge from the examination of things which actually have been. It is in this manner, that intention may be found in nature; but this intention is not to be supposed, or vainly imagined, from what we may conceive to be.

We have been now supposing, that the beginning of our present earth had been laid in the bottom of the ocean, at the completion of the former land; but this was only for the sake of distinctness. The just view is this, that when the former land of the globe had been complete, so as to begin to waste and be impaired by the encroachment of the sea, the present land began to appear above the surface of the ocean. In this manner we suppose a due proportion to be always preserved of land and water upon the surface of the globe, for the purpose of a habitable world, such as this which we possess. We thus, also, allow time and opportunity for the translation of animals and plants to occupy the earth.

But, if the earth on which we live, began to appear in the ocean at the time when the last began to be resolved, it could not be from the materials of the continent immediately preceding this which we examine, that the present earth had been constructed; for the bottom of the ocean must have been filled with materials before land could be made to appear above its surface.

Let us suppose that the continent, which is to succeed our land, is at present beginning to appear above the water in the middle of the Pacific Ocean, it must be evident, that the materials of this great body, which is formed and ready to be brought forth, must have been collected from the destruction of an earth, which does not now appear. Consequently, in this true statement of the case, there is necessarily required the destruction of an animal and vegetable earth prior to the former land; and the materials of that earth which is first in our account, must have been collected at the bottom of the ocean, and begun to be concocted for the production of the present earth, when the land immediately preceding the present had arrived at its full extent.

This, however, alters nothing with regard to the nature of those operations of the globe. The system is still the same. It only protracts the indefinite space of time in its existence, while it gives us a view of another distinct period of the living world; that is to say, the world which we inhabit is composed of the materials, not of the earth which was the immediate predecessor of the present, but of the earth which, in ascending from the present, we consider as the third, and which had preceded the land that was above the surface of the sea, while our present land was yet beneath the water of the ocean. Here are three distinct successive periods of existence, and each of these is, in our measurement of time, a thing of indefinite duration.

We have now got to the end of our reasoning; we have no data further to conclude immediately from that which actually is: But we have got enough; we have the satisfaction to find, that in nature there is wisdom, system, and consistency. For having, in the natural history of this earth, seen a succession of worlds, we may from this conclude that there is a system in nature; in like manner as, from seeing revolutions of the planets, it is concluded, that there is a system by which they are intended to continue those revolutions. But if the succession of worlds is established in the system of nature, it is in vain to look for any thing higher in the origin of the earth. The result, therefore, of this physical inquiry is, that we find no vestige of a beginning,—no prospect of an end.



CHAPTER II.

An Examination of Mr KIRWAN'S Objections to the Igneous Origin of Stony Substances.

A theory which is founded on a new principle, a theory which has to make its way in the public mind by overturning the opinions commonly received by philosophising men, and one which has nothing to recommend it but the truth of its principles, and the view of wisdom or design to which it leads, neither of which may perhaps be perceived by the generality of people, such a theory, I say, must meet with the strongest opposition from the prejudices of the learned, and from the superstition of those who judge not for themselves in forming their notions, but look up to men of science for authority. Such is the case with some part of the Theory of the Earth, which I have given, and which will probably give offence to naturalists who have espoused an opposite opinion. In order, then, to obtain the approbation of the public, it may not be enough to give a theory that should be true, or altogether unexceptionable it may be necessary to defend every point that shall be thought exceptionable by other theorists, and to show the fallacy of every learned objection that may be made against it. It is thus, in general, that truth and error are forced to struggle together, in the progress of science; and it is only in proportion as science removes erroneous conceptions, which are necessarily in the constitution of human knowledge, that truth will find itself established in natural philosophy.

Mr Kirwan has written a dissertation, entitled, Examination of the Supposed Igneous Origin of Stony Substances, which was read in the Royal Irish Academy. The object of that dissertation is to state certain objections, which have occurred to him, against the Theory of the Earth published in the Transactions of the Edinburgh Royal Society; and he has attacked that theory in all the points where it appears to him to be vulnerable. It is to these objections that I am now to give an answer. The authority given to this dissertation, by the Royal Irish Academy, as well as the reputation of the author, make it necessary for me to endeavour to put in their true light the facts alleged in that performance, and to analyse the arguments employed, in order to judge of the reasoning by which the theory of mineral fusion is refuted in this Examination.

A theory founded on truth, and formed according to the proper rules of science, can ever suffer from a strict examination, by which it would be but the more and more confirmed. But, where causes are to be traced through a chain of various complicated effects, an examination not properly conducted upon accurate analytical principles, instead of giving light upon a subject in which there had been obscurity and doubt, may only serve to perplex the understanding, and bring confusion into a subject which was before sufficiently distinct. To redress that evil, then, must require more labour and some address; and this is an inconveniency that may be looked for, more or less, in every controversial discussion.

I do not mean to enter any farther into the defence of my theory in this chapter, than what is necessary to answer a man of science and respectability, who has stated his objections. The observations which he has made appear to me to be founded on nothing more than common prejudice, and misconceived notions of the subject. I am therefore to point out that erroneous train of reasoning, into which a hasty superficial view of things, perhaps, has led the patron of an opposite opinion to see my theory in an unfavourable light. This, however, is not all; for, that train of inconsequential reasoning is so congenial with the crude and inconsiderate notion generally entertained, of solid mineral bodies having been formed by the infiltration of water into the earth, that no opportunity should be lost of exposing an erroneous manner of reasoning, which is employed in supporting a hypothesis founded upon certain operations of the surface of this earth that cannot be properly applied to the formation of mineral bodies. This object, therefore, so far as it may come in the way, will be attended to in this discussion, although I shall have another opportunity of farther enlarging upon that subject.

Our author begins by examining a geological operation, the very opposite to that of mineral consolidation, and which would seem to have little connection with the subject of this dissertation. In my theory, I advanced two propositions with regard to the economy of this world: First, That the solid masses of this earth, when exposed to the atmosphere, decay, and are resolved into loose materials, of which the vegetable soil upon the surface is in part composed; and, secondly, That these loose materials are washed away by the currents of water, and thus carried at last into the sea. Our author says "Here are two suppositions, neither of which is grounded on facts;" and yet he has but the moment before made the following confession: "That the soil, however, receives an increase from some species of stones that moulder by exposition to the air cannot be denied, but there is no proof that all soil has arisen from decomposition."—Surely all soil, that is made from the hard and compact body of the land, which is my proposition, must have arisen from decomposition; and I have no where said, that all the soil of this earth is made from the decomposition or detritus of those stony substances; for, masses of looser sand and softer substances contribute still more to the formation of vegetable soils.

With regard to the other proposition, our author says, "Soil is not constantly carried away by the water, even from mountains."—I have not said that it is constantly washed away; for, while it is soil in which plants grow, it is not travelling to the sea, although it be on the road, and must there arrive in time. I have said, that it is necessarily washed away, that is, occasionally. M. de Luc's authority is then referred to, as refuting this operation of water and time upon the soil. Now, I cannot help here observing, that our author seems to have as much misapprehended M. de Luc's argument as he has done mine. That philosopher, in his letters to the Queen, has described most accurately the decay of the rocks and solid mountains of the Alps and Jura, and the travelling of their materials by water, although he does not carry them to the sea. It is true, indeed, that this author, who supposes the present earth on which we dwell very young, is anxious to make an earth, in time, that shall not decay nor be washed away at all; but that time is not come yet; therefore the authority, here given against my theory, is the speculative supposition, or mere opinion, of a natural philosopher, with regard to an event which may never come to pass, and which I shall have occasion to consider fully in another place.

Our author had just now said, that I have advanced two suppositions, neither of which is grounded on facts: Now, with regard to the one, he has acknowledged, that the mouldering of stones takes place, which is the fact on which that proposition is grounded; and with regard to the other, the only authority given against it is founded expressly upon the moving of soil by means of the rain water, in order to make sloping plains of mountains. Here, therefore, I have grounded my propositions upon facts; and our author has founded his objections, first, upon a difficulty which he has himself removed; and, secondly, upon nothing but a visionary opinion, with regard to an earth which is not yet made, and which, when once made, is never more to change.

After making some unimportant observations,—of all water not flowing into the sea,—and of the travelled materials being also deposited upon the plains, etc. our author thus proceeds: "Hence the conclusion of our author relative to the imperfect constitution of the globe falls to the ground; and the pains he takes to learn, by what means a decayed world may be renovated, are superfluous."—The object of my theory is to show, that this decaying nature of the solid earth is the very perfection of its constitution, as a living world; therefore, it was most proper that I should take pains to learn by what means the decayed parts might be renovated. It is true, indeed, that this will be superfluous, when once that constitution of the earth, which M. de Luc thinks is preparing, shall be finished; but, in the mean time, while rivers carry the materials of our land, and while the sea impairs the coast, I may be allowed to suppose that this is the actual constitution of the earth.

I cannot help here animadverting upon what seems to be our author's plan, in making these objections, which have nothing to do with his examination. He accuses me of giving this world a false or imperfect constitution, (in which the solid land is considered as resolvable, and the materials of that land as being washed away into the sea,) for no other reason, that I can see, but because this may imply the formation of a future earth, which he is not disposed to allow; and, he is now to deny the stratified construction of this present earth to have been made by the deposits of materials at the bottom of the sea, because that would prove the existence of a former earth, which is repugnant to his notion of the origin of things, and is contrary, as he says, to reason, and the tenor of the Mosaic history. Let me observe, in passing, that M. de Luc, of whose opinions our author expresses much approbation, thinks that he proves, from the express words and tenor of the Mosaic history, that the present earth was at the bottom of the sea not many years ago, and that the former earth had then disappeared.

But, what does our author propose to himself, in refusing to admit my view of the operations which are daily transacting upon the surface of this earth, where there is nothing dark or in the least mysterious, as there may be in the mineral regions? Does he mean to say, that it is not the purpose of this world to provide soil for plants to grow in? Does he suppose that this soil is not moveable with the running water of the surface? and, Does he think that it is not necessary to replace that soil which is removed? This is all that I required in that constitution of the world which he has thus attacked; and I wish that he or any person would point out, in what respect I had demanded any thing unreasonable, or any thing that is not actually to be observed every day.

Thus I have endeavoured to show, that our author has attacked my theory in a part where I believe it must be thought invulnerable; but this is only, I presume, in order that he may make an attack with more advantage upon another part, viz. the composition of strata from the materials of an earth thus worn out in the service of vegetation,—materials which are necessarily removed in order to make way for that change of things in which consists the active and living system of this world. If he succeed in this attempt to refute my theory of the original formation of strata, he would then doubtless find it more easy to persuade philosophers that the means which I employ in bringing those materials again to light, when transformed into such solid masses as the system of this earth requires, are extravagant, unnatural, and unnecessary. Let us then see how he sets about this undertaking.

With regard to the composition of the earth, it is quoted from my theory, that the solid parts of the globe are in general composed of sand, gravel, argillaceous and calcareous strata, or of various compositions of these with other substances; our author then adds, "This certainly cannot be affirmed as a fact, but rather the contrary; it holds only true of the surface, the basis of the greater part of Scotland is evidently a granitic rock, to say nothing of the continents, both of the Old and New World, according to the testimony of all mineralogists." This proposition, with regard to the general composition of the earth, I have certainly not assumed, I have maintained it as a fact, after the most scrupulous examination of all that, with the most diligent search, I have been able to see, and of all that authors have wrote intelligibly upon the subject. If, therefore, I have so misrepresented this great geological fact on which my theory is absolutely founded, I must have erred with open eyes; and my theory of the earth, like others which have gone before it, will, upon close examination, appear to be unfounded, as the dissertation now before us is endeavouring to represent it.

Our author here, I think, alleges that the contrary to this, my fundamental proposition, is the truth; and he has given us Scotland as an example in which his assertion (founded upon the testimony of all mineralogists), is illustrated. Now my geological proposition should certainly be applicable to Scotland, which is the country that I ought to be best acquainted with; consequently, if what our author here asserts be true, I would have deserved that blame which he is willing to throw on me. Let me then beg the readers attention for a moment, that I may justify myself from that charge, and place in its proper light this authority, upon so material a point in geology.

I had examined Scotland from the one end to the other before I saw one stone of granite in its native place, I have moreover examined almost all England and Wales, (excepting Devonshire and Cornwall) without seeing more of granite than one spot, not many hundred yards of extent; this is at Chap; and I know, from information, that there is another small spot in the middle of England where it is just seen. But, let me be more particular with regard to Scotland, the example given in proof.

I had travelled every road from the borders of Northumberland and Westmoreland to Edinburgh; from Edinburgh, I had travelled to Port-Patrick, and from that along the coast of Galloway and Airshire to Inverary in Argyleshire, and I had examined every spot between the Grampians and the Tweedale mountains from sea to sea, without seeing granite in its place. I had also travelled from Edinburgh by Grief, Rannock, Dalwhiny, Fort Augustus, Inverness, through east Ross and Caithness, to the Pentland-Frith or Orkney islands, without seeing one block of granite in its place. It is true, I met with it on my return by the east coast, when I just saw it, and no more, at Peterhead and Aberdeen; but that was all the granite I had ever seen when I wrote my Theory of the Earth. I have, since that time, seen it in different places; because I went on purpose to examine it, as I shall have occasion to describe in the course of this work.

I may now with some confidence affirm, from my own observation, and from good information with regard to those places where I have not been, except the northwest corner, I may affirm, I say, that instead of the basis of the greatest part of Scotland being a granitic rock, which our author has maintained as an evident thing, there is very little of it that is so; not perhaps one five hundred part. So far also as I am to judge from my knowledge of the mineral construction of England and Wales, which I have examined with the greatest care, and from the mineral chart which my friend Mr Watt made for me from his knowledge of Cornwall, I would say that there is scarcely one five hundred part of Britain that has granite for its basis. All the rest, except the porphyry and basaltes, consists of stratified bodies, which are composed more or less of the materials which I mentioned, generally, in the above quotation, and which our author would dispute.

But do not let me take the advantage of this error of our author with regard to the mineralogy of Scotland, and thus draw what may be thought an undue conclusion in favour of my general theory; let us go over and examine the continent of Europe, and see if it is any otherwise there than in Britain. From the granite of the Ural mountains, to that which we find in the Pyrenees, there is no reason, so far as I have been able to learn, to conclude that things are formed either upon any other principle, or upon a different scale. But, instead of one five hundred part, let us suppose there to be one fiftieth part of the earth in general resting upon granite, I could not have expressed myself otherwise than I have done; for, when I maintained that the earth in general consisted of stratified bodies, I said that this was only nine tenths, or perhaps ninety-nine hundredths of the whole, and I mentioned that there were other masses of a different origin, which should be considered separately. Our author, on the contrary, asserts that the Old and New Worlds, as well as Scotland, are placed upon granite as a basis, which he says is according to the testimony of all mineralogists. I shall have occasion to examine this opinion of mineralogists, in comparing it with those masses of granite which appear to us; and I hope fully to refute the geological, as well as mineralogical notions with regard to that body. In the mean time, let me make the following reflection, which here naturally occurs.

My Theory of the Earth is here examined,—not with the system of nature, or actual state of things, to which it certainly should have corresponded,—but with the systematic views of a person, who has formed his notions of geology from the vague opinion of others, and not from what he has seen. Had the question been, How far my theory agreed with other theories, our author might very properly have informed his readers that it was diametrically opposite to the opinions of mineralogists; but, this was no reason for concluding it to be erroneous; on the contrary, it is rather a presumption that I may have corrected the error of mineralogists who have gone before me, in like manner as it is most reasonable to presume that our author may have corrected mine. Let us then proceed to examine how far this shall appear to be the case.

Our author has stated very fairly from the Theory, viz. That all the strata of the earth, not only those consisting of calcareous masses, but others superincumbent on these, have had their origin at the bottom of the sea, by the collection of sand, gravel, shells, coralline, and crustaceous bodies, and of earths and clays variously mixed, separated, and accumulated. He then adds, "Various geological observations contradict this conclusion. There are many stratified mountains of argillaceous slate, gneiss, serpentine, jasper, and even marble, in which either sand, gravel, shells, coralline, or crustaceous bodies are never, or scarce ever found."

Here our author seems to have deceived himself, by taking a very partial view of things which should be fully examined, and well understood, before general conclusions are to be drawn from those appearances; for, although those particular objects may not be visible in the strata which he has enumerated, or many others, they are found in those strata which are either immediately connected and alternated with them, or with similar strata; something to that purpose I think I have said; and, if I had not, it certainly requires no deep penetration to have seen this clear solution of that appearance of those objects not being found in every particular stratum. He says that those marks of known materials are never or scarce ever found;—by scarce ever he surely means that they are sometimes found; but if they shall only once be found, his argument is lost. I have not drawn my geological conclusion from every particle in strata being distinguishable, but from there being certain distinguishable particles in strata, and from our knowing what had been the former state and circumstances of those distinguished parts.

If every stone or part of a stratum, in which those known objects are not immediately visible, must be considered as so many geological observations that contradict my theory, (of strata being formed from the materials of a former earth), then, surely every stone and every stratum which visibly contains any of those materials, must prove my theory. But if every stratum, where these are found in any part of it, is to be concluded as having had its origin at the bottom of the sea; and, if every concomitant stratum, though not having those objects visible or sufficiently distinct, must be considered as having had the same or a similar origin, that pretended contradiction of my theory comes to no more than this, that every individual stone does not bear in it the same or equal evidence of that general proposition which necessarily results from the attentive consideration of the whole, including every part.

But to see how necessary it is to judge in this manner, not partially, but upon the whole, we may observe, that there are two ways by which the visible materials or distinguishable bodies of a former earth, not only may be rendered invisible in the composition of our present earth, but must be so upon many occasions. These are, first, by mechanical comminution, which necessarily happens, more or less, in that operation by which bodies are moved against one another, and thus transported from the land to the bottom of the deepest seas; secondly, by chemical operations, (whatever these may be, whether the action of water or of fire, or both), which are also necessarily employed for consolidating those loose materials, that are to form the rocks and stones of this earth, and by means of which those materials are to have their distinguishable shapes affected in all degrees and obliterated. Therefore, to demand the visible appearance of those materials in every stratum of the earth, or in every part of a stratum, is no other than to misunderstand the subject altogether. The geological observations, which have been thus alleged as contradicting my theory, are stratified bodies, containing proofs of the general origin which I attribute to the earth, but proofs which may not always be seen with equal facility as those which even convince the vulgar.

Our author has surely perplexed himself with what writers of late have said concerning primitive mountains as they are called, a subject of deeper search, than is commonly imagined, as I hope to show in the course of this work. It is an interesting subject of investigation, as giving us the actual view of those operations of nature which, in forming my Theory of the Earth, more general principles had led me to conclude might be. But, it is a subject which, I am afraid, will lead me to give farther offence to our author, however innocent I may be in giving nothing but what I have from nature.

The reason for saying so is this; I am blamed for having endeavoured to trace back the operations of this world to a remote period, by the examination of that which actually appears, contrary, as is alleged, "to reason, and the tenor of the Mosaic history, thus leading to an abyss, from which human reason recoils, etc." In a word, (says our author), "to make use of his own expression, We find no vestige of a beginning. Then this system of successive worlds must have been eternal." Such is the logic by which, I suppose, I am to be accused of atheism. Our author might have added, that I have also said—we see no prospect of an end; but what has all this to do with the idea of eternity? Are we, with our ideas of time, (or mere succession), to measure that of eternity, which never succeeded any thing, and which will never be succeeded? Are we thus to measure eternity, that boundless thought, with those physical notions of ours which necessarily limit both space and time? and, because we see not the beginning of created things, Are we to conclude that those things which we see have always been, or been without a cause? Our author would thus, inadvertently indeed, lead himself into that gulf of irreligion and absurdity into which, he alleges, I have boldly plunged.

In examining this present earth, we find that it must have had its origin at the bottom of the sea, although our author seems willing to deny that proposition. Farther, in examining the internal construction of this stratified and sea-born mass, we find that it had been composed of the moved materials of a former earth; and, from the most accurate and extensive examination of those materials, which in many places are indeed much disguised, we are led necessarily to conclude, that there had been a world existing, and containing an animal, a vegetable, and a mineral system. But, in thus tracing back the natural operations which have succeeded each other, and mark to us the course of time past, we come to a period in which we cannot see any farther. This, however, is not the beginning of those operations which proceed in time and according to the wise economy of this world; nor is it the establishing of that, which, in the course of time, had no beginning; it is only the limit of our retrospective view of those operations which have come to pass in time, and have been conducted by supreme intelligence.

My principal anxiety was to show how the constitution of this world had been wisely contrived; and this I endeavoured to do, not from supposition or conjecture, but from its answering so effectually the end of its intention, viz. the preserving of animal life, which we cannot doubt of being its purpose. Here then is a world that is not eternal, but which has been the effect of wisdom or design.

With regard again to the prospective view of the creation, How are we to see the end of that wise system of things which so properly fulfils the benevolent intention of its maker,—in giving sustenance to the animal part, and information to intellectual beings, who, in these works of nature, read what much concerns their peace of mind,—their intellectual happiness? What then does our author mean, in condemning that comprehensive view which I have endeavoured to take of nature? Would he deny that there is to be perceived wisdom in the system of this world, or that a philosopher, who looks into the operations of nature, may not plainly read the power and wisdom of the Creator, without recoiling, as he says, from the abyss? The abyss, from which a man of science should recoil, is that of ignorance and error.

I have thus shown, that, from not perceiving the wise disposition of things upon the surface of this earth for the preservation of vegetable bodies, our author has been led to deny the necessary waste of the present earth, and the consequent preparation of materials for the construction of another; I have also shown, that he denies the origin which I had attributed to the stratified parts of this earth, as having been the collection of moving materials from a former earth; and now I am come to consider the professed purpose of this paper, viz. the examination of solid stony substances which we find in those strata of our earth, as well as in more irregular masses. Here, no doubt, my theory would have been attacked with greater success, had our author succeeded in pointing out its error with regard to the original composition of those indurated bodies, to which I ascribe fusion as the cause of their solidity. For, if we should, according to our author's proposition, consider those consolidated bodies as having been originally formed in that solid state, here the door might be shut against any farther investigation;—But to what purpose?—Surely not to refute my theory, but to explode every physical inquiry farther on the subject, and thus to lead us back into the science of darkness and of scepticism. But let us proceed to see our author's sentiments on this subject.

As I had proved from matter of fact, or the actual appearances of nature, that all the strata of the earth had been formed at the bottom of the sea, by the subsidence of those materials which either come from the decaying land, or are formed in the sea itself, it was necessary that I should consider in what manner those spongy or porous bodies of loose materials, gathered together at the bottom of the sea, could have acquired that consolidated state in which we find them, now that they are brought up to our examination. Upon this occasion, our author says, "The particles which now form the solid parts of the globe need not be supposed to have originally been either spongy or porous, the interior parts at the depth of a few miles might have been originally, as at present, a solid mass." If, indeed, we shall make that supposition, we may then save ourselves the trouble of considering either how the strata of the earth have been formed or consolidated; for, they might have been so originally. But, how can a naturalist who had ever seen a piece of Derbyshire marble, or any other shell limestone, make that supposition? Here are, to the satisfaction of every body of common understanding who looks at them, bodies which are perfectly consolidated, bodies which have evidently been formed at the bottom of the sea, and therefore which were not originally a solid mass. Mr Bertrand, it is true, wrote a book to prove that those appearances were nothing but a lusus naturae; and, I suppose he meant, with our author, that those strata had been also originally, as at present, a solid mass.

With regard to the consolidation of strata, that cardinal point for discussion, our author gives the following answer: "Abstracting from his own gratuitous hypothesis, it is very easy to satisfy our author on this head; the concreting and consolidating power in most cases arises from the mutual attraction of the component particles of stones to each other." This is an answer with regard to the concreting power, a subject about which we certainly are not here inquiring. Our author, indeed, has mentioned a consolidating power; but that is an improper expression; we are here inquiring, How the interstices, between the collected materials of strata, deposited at the bottom of the sea, have been filled with a hard substance, instead of the fluid water which had originally occupied those spaces. Our author then continues; "If these particles leave any interstices, these are filled with water, which no ways obstructs their solidity when the points of contact are numerous; hence the decrepitation of many species of stones when heated."

If I understand our author's argument, the particles of stone are, by their mutual attractions, to leave those hard and solid bodies which compose the strata, that is to say, those hard bodies are to dissolve themselves; but, To what purpose? This must be to fill up the interstices, which we must suppose occupied by the water. In that case, we should find the original interstices filled with the substances which had composed the strata, and we should find the water translated into the places of those bodies; here would be properly a transmutation, but no consolidation of the strata, such as we are here to look for, and such as we actually find among those strata. It may be very easy for our author to form those explanations of natural phenomena; it costs no tedious observation of facts, which are to be gathered with labour, patience, and attention; he has but to look into his own fancy, as philosophers did in former times, when they saw the abhorrence of a vacuum and explained the pump. It is thus that we are here told the consolidation of strata arises from the mutual attraction of the component particles of stones to each other; the power, by which the particles of solid stony bodies retain their places in relation to each other, and resist separation from the mass, may, no doubt, be properly enough termed their mutual attractions; but we are not here inquiring after that power; we are to investigate the power by which the particles of hard and stony bodies had been separated, contrary to their mutual attractions, in order to form new concretions, by being again brought within the spheres of action in which their mutual attractions might take place, and make them one solid body. Now, to say that this is by their mutual attraction, is either to misunderstand the proper question, or to give a most preposterous answer.

It is not every one who is fit to reason with regard to abstract general propositions; I will now, therefore, state a particular case, in illustration of that proposition which has been here so improperly answered. The strata of Derbyshire marbles were originally immense collections at the bottom of the sea, of calcareous bodies consisting almost wholly of various fragments of the entrochi; and they were then covered with an indefinite number of other strata under which these entrochi must have been buried. In this original state of those strata, I suppose the interstices between the fragments of the coralline bodies to have been left full of sea-water; at present we find those interstices completely filled with a most perfectly solid body of marble; and the question is, whether that consolidating operation has been the work of water and solution, by our naturalist's termed infiltration; or if it has been performed, as I have maintained, by the softening power or heat, or introduction of matter in the fluid state of fusion. Our author does not propose any other method for the consolidation of those loose and incoherent bodies, but he speaks of the mutual attraction of the component particles of stone to each other; Will that fill the interstices between the coralline bodies with solid marble, as well as consolidate the coralline bodies themselves? or, if it should, How are those interstices to be thus filled with a substance perfectly different from the deposited bodies, which is also frequently the case? But, how reason with a person who, with this consolidation of strata, confounds the well known operation by which the mortar, made with caustic lime and sand, becomes a hard body! One would imagine that he were writing to people of the last age, and not to chemical philosophers who know so well how that mortar is concreted.

To my argument, That these porous strata are found consolidated with every different species of mineral substance, our author makes the following observation: "Here the difficulties to the supposition of an aqueous solution are placed in the strongest light; yet it must be owned that they partly arise from the author's own gratuitous supposition, that strata existed at the bottom of the sea previous to their consolidation;"—gratuitous supposition!—so far from being a supposition of any kind, it is a self evident proposition; the terms necessarily imply the conclusion. I beg the readers attention for a moment to this part of our author's animadversion, before proceeding to consider the whole; for, this is a point so essential in my theory, that if it be a gratuitous supposition, as is here asserted, it would certainly be in vain to attempt to build upon it the system of a world.

That strata may exist, whether at the bottom of the sea, or any other where, without being consolidated, will hardly be disputed; for, they are actually found consolidated in every different degree. But, when strata are found consolidated, at what time is it that we are to suppose this event to have taken place, or this accident to have happened to them?—Strata are formed at the bottom of water, by the subsidence or successive deposits of certain materials; it could not therefore be during their formation that such strata had been consolidated; consequently, we must necessarily conclude, without any degree of supposition, that strata had existed at the bottom of the sea previous to their consolidation, unless our author can show how they may have been consolidated previous to their existing.

This then is what our author has termed a gratuitous supposition of mine, and which, he adds, "is a circumstance which will not be allowed by the patrons of the aqueous origin of stony substances, as we have already seen."—I am perfectly at a loss to guess at what is here alluded to by having been already seen, unless it be that which I have already quoted, concerning things which have been never seen, that is, those interior parts of the earth which were originally a solid mass.—I have hardly patience to answer such reasoning;—a reasoning which is not founded upon any principle, which holds up nothing but chimera to our view, and which ends in nothing that is intelligible;—but, others, perhaps, may see this dissertation of our author's in a different light; therefore, it is my duty to analyse the argument, however insignificant it may seem to me.

I have minutely examined all the stratified bodies which I have been able, during a lifetime, to procure, both in this country of Britain, and from all the quarters of the globe; and the result of my inquiry has been to conclude, that there is nothing among them in an original state, as the reader will see in the preceding chapter. With regard again to the masses which are not stratified, I have also given proof that they are not in their original state, such as granite, porphyry, serpentine, and basaltes; and I shall give farther satisfaction, I hope, upon that head, in the course of this work. I have therefore concluded, That there is nothing to be found in an original state, so far as we see, in the construction of this earth. But, our author answers, That the interior parts might have been in an original state of solidity.—So might they have been upon the surface of the earth, or on the summits of our mountains; but, we are not inquiring What they might have been, but What they truly are. It is from this actual state in which the solid parts of the earth are found, that I have endeavoured to trace back the different states in which they must have been; and, by generalising facts, I have formed a theory of the earth. If this be a wrong principle or manner of proceeding in a physical investigation, or if, proceeding upon that principle, I have made the induction by reasoning improperly on any occasion, let this be corrected by philosophers, who may reason more accurately upon the subject. But to oppose a physical investigation with this proposition, that things might have been otherwise, is to proceed upon a very different principle,—a principle which, instead of tending to bring light out of darkness, is only calculated to extinguish that light which we may have acquired.

I shall afterwards have occasion to examine how far the philosophers, who attribute to aqueous solution the origin of stony substances, have proceeded in the same inductive manner of reasoning from effect to cause, as they ought to do in physical subjects, and not by feigning causes, or following a false analogy; in the mean time, I am to answer the objections which have been made to the theory of the earth.

In opposition to the theory of consolidating bodies by fusion, our author has taken great pains to show, that I cannot provide materials for such a fire as would be necessary, nor find the means to make it burn had I those materials. Had our author read attentively my theory he would have observed, that I give myself little or no trouble about that fire, or take no charge with regard to the procuring of that power, as I have not founded my theory on the supposition of subterraneous fire, however that fire properly follows as a conclusion from those appearances on which the theory is founded. My theory is founded upon the general appearances of mineral bodies, and upon this, that mineral bodies must necessarily have been in a state of fusion. I do not pretend to prove, demonstratively, that they had been even hot, however that conclusion also naturally follows from their having been in fusion. It is sufficient for me to demonstrate, That those bodies must have been, more or less, in a state of softness and fluidity, without any species of solution. I do not say that this fluidity had been without heat; but, if that had been the case, it would have answered equally well the purpose of my theory, so far as this went to explain the consolidation of strata or mineral bodies, which, I still repeat, must have been by simple fluidity, and not by any species of solution, or any other solvent than that universal one which permeates all bodies, and which makes them fluid.

Our author has justly remarked the difficulty of fire burning below the earth and sea. It is not my purpose here to endeavour to remove those difficulties, which perhaps only exist in those suppositions which are made on this occasion; my purpose is to show, that he had no immediate concern with that question, in discussing the subject of the consolidation which we actually find in the strata of the earth, unless my theory, with regard to the igneous origin of stony substances, had proceeded upon the supposition of a subterraneous fire. It is surely one thing to employ fire and heat to melt mineral bodies, in supposing this to be the cause of their consolidation, and another thing to acknowledge fire or heat as having been exerted upon mineral bodies, when it is clearly proved, from actual appearances, that those bodies had been in a melted state, or that of simple fluidity. Here are distinctions which would be thrown away upon the vulgar; but, to a man of science, who analyses arguments, and reasons strictly from effect to cause, this is, I believe, the proper way of coming at the truth. If the patrons of the aqueous origin of stony substances can give us any manner of scientifical, i.e. intelligible investigation of that process, it shall be attended to with the most rigid impartiality, even by a patron of the igneous origin of those substances, as he wishes above all things to distinguish, in the mineral operations, those which, on the one hand, had been the effect of water, from those which, on the other hand, had been the immediate effect of fire or fusion;—this has been my greatest study. But, while mineralists or geologists give us only mere opinions, What is science profited by such inconsequential observations, as are founded upon nothing but our vulgar notions? Is the figure of the earth, e.g. to be doubted, because, according to the common notion of mankind, the existence of an antipod is certainly to be denied?

I am not avoiding to meet that question with regard to the providing of materials for such a mineral fire as may be required; no question I desire more to be asked to resolve; but it must not be in the manner that our author has put that question. He has included this supposed difficulty among a string of other arguments by which he would refute my theory with regard to the igneous origin of stony substances, as if I had made that fire a necessary condition or a principle in forming my theory of consolidation. Now, it is precisely the reverse; and this is what I beg that mineral philosophers will particularly attend to, and not give themselves so much unnecessary trouble, and me so disagreeable a talk. I have proved that those stony substances have been in the fluid state of fusion; and from this, I have inferred the former existence of an internal heat, a subterraneous fire, or a certain cause of fusion by whatever name it shall be called, and by whatever means it shall have been procured. The nature of that operation by which strata had been consolidated, like that by which they had been composed, must, according to my philosophy, be decided by ocular demonstration; from examining the internal evidence which is to be found in those bodies as we see them in the earth; because the consolidating operation is not performed in our sight, no more than their stratification which our author has also denied to have been made, as I have said, by the deposits of materials at the bottom of the sea. Now, with regard to the means of procuring subterraneous fire, if the consolidating operation shall be thus decided to have been that of fusion, as I think I have fully shown, and for which I have as many witnesses, perhaps as there are mineral bodies, then our author's question, (how I am to procure a fire) in the way that he has put it, as an argument against the fusion, would be at least useless; for, though I should here confess my ignorance with regard to the means of procuring fire, the evidence of the melting operation, or former fluidity of those mineral bodies, would not be thereby in the least diminished. If again no such evidence for the fusion of those bodies shall appear, and it be concluded that they had been consolidated by the action of water alone, as our author seems inclined to maintain, he would have no occasion to start difficulties about the procuring of fire, in order to refute a theory which then would fall of itself as having no foundation.

But in order to see this author's notion of the theory which he is here examining, it may be proper to give a specimen of his reasoning upon this subject of heat. He says, "That my supposition of heat necessary for consolidating strata is gratuitous, not only because it is unnecessary, as we have already shown, but also because it is inconsistent with our author's own theory." Let us now consider those two propositions. First, it is unnecessary, as we have already shown;—I have already taken particular notice of what we have been shown on this occasion, viz. That the earth at a certain depth may have been originally in a solid state; and, that, where it is to be consolidated, this is done by the mutual attraction of the stony particles. Here is all that we have been shown to make subterraneous heat, for the consolidation of strata, unnecessary; and now I humbly submit, if this is sufficient evidence, that mineral heat is a gratuitous supposition.

Secondly, "it is inconsistent with our author's own theory." Here I would beg the readers attention to the reasoning employed on this occasion. He says, "according to him these strata, which were consolidated by heat, were composed of materials gradually worn from a preceding continent, casually and successively deposited in the sea; Where then will he find, and how will he suppose, to have been formed those enormous masses of sulphur, coal, or bitumen, necessary to produce that immense heat necessary for the fusion of those vast mountains of stone now existing? All the coal, sulphur, and bitumen, now known, does not form the 100,000 part of the materials deposited within one quarter of a mile under the surface of the earth; if, therefore, they were, as his hypothesis demands, carried off and mixed with the other materials, and not formed in vast and separate collections, they could never occasion, by their combustion, a heat capable of producing the smallest effect, much less those gigantic effects which he requires."