Theory of the Earth, With Proofs and Illustrations, Volume 1 (of 4)

by James Hutton

CHAP. III.

Of Physical Systems, and Geological Theories, in general.

In the first chapter I have given a general theory of the earth, with such proofs as I thought were sufficient for the information of intelligent men, who might satisfy themselves by examining the facts on which the reasoning in that theory had been founded.

In the second chapter, I have endeavoured to remove the objections which have been made to that theory, by a strenuous patron of the commonly received opinion of mineralogists and geologists,—an opinion which, if not diametrically opposite, differs essentially from mine. But now I am to examine nature more particularly, in order to compare those different opinions with the actual state of things, on which every physical theory must be founded. Therefore, the opinions of other geologists should be clearly stated, that so a fair comparison may be made of theories which are to represent the system of this earth.

Now, if I am to compare that which I have given as a theory of the earth, with the theories given by others under that denomination, I find so little similarity, in the things to be compared, that no other judgment could hence be formed, perhaps, than that they had little or no resemblance. I see certain treatises named Theories of the Earth; but, I find not any thing that entitles them to be considered as such, unless it be their endeavouring to explain certain appearances which are observed in the earth. That a proper theory of the earth should explain all those appearances is true; but, it does not hold, conversely, that the explanation of an appearance should constitute a theory of the earth. So far as the theory of the earth shall be considered as the philosophy or physical knowledge of this world, that is to say, a general view of the means by which the end or purpose is attained, nothing can be properly esteemed such a theory unless it lead, in some degree, to the forming of that general view of things. But now, let us see what we have to examine in that respect.

We have, first, Burnet's Theory of the Earth. This surely cannot be considered in any other light than as a dream, formed upon the poetic fiction of a golden age, and that of iron which had succeeded it; at the same time, there are certain appearances in the earth which would, in a partial view of things, seem to justify that imagination. In Telliamed, again, we have a very ingenious theory, with regard to the production of the earth above the surface of the sea, and of the origin of those land animals which now inhabit that earth. This is a theory which has something in it like a regular system, such as we might expect to find in nature; but, it is only a physical romance, and cannot be considered in a serious view, although apparently better founded than most of that which has been wrote upon the subject.

We have then a theory of a very different kind; this is that of the Count de Buffon. Here is a theory, not founded on any regular system, but upon an irregularity of nature, or an accident supposed to have happened to the sun. But, are we to consider as a theory of the earth, an accident by which a planetary body had been made to increase the number of these in the solar system? The circumvolution of a planetary body (allowing it to have happened in that manner) cannot form the system of a world, such as our earth exhibits; and, in forming a theory of the earth, it is required to see the aptitude of every part of this complicated machine to fulfil the purpose of its intention, and not to suppose the wise system of this world to have arisen from, the cooling of a lump of melted matter which had belonged to another body. When we consider the power and wisdom that must have been exerted in the contriving, creating, and maintaining this living world which sustains such a variety of plants and animals, the revolution of a mass of dead matter according to the laws of projectiles, although in perfect wisdom, is but like a unite among an infinite series of ascending numbers.

After the theory of that eloquent writer, founded on a mere accident, or rather the error of a comet which produced the beautiful system of this world, M. de Luc, in his Theory of the earth, has given us the history of a disaster which befell this well contrived world;—a disaster which caused the general deluge, and which, without a miracle, must have undone a system of living beings that are so well adapted to the present state of things. But, surely, general deluges form no part of the theory of the earth; for, the purpose of this earth is evidently to maintain vegetable and animal life, and not to destroy them.

Besides these imaginary great operations in the natural history of this earth, we have also certain suppositions of geologists and mineralists with regard to the effect of water, for explaining to us the consolidation of the loose materials of which the strata of the earth had been composed, and also for producing every other appearance, or any which shall happen to occur in the examination of the earth, and require to be explained. That this is no exaggerated representation, and that this is all we have as a theory, in the suppositions of those geologists, will appear from the following state of the case.

They suppose water the agent employed in forming the solid bodies of the earth, and in producing those crystallised bodies which appear in the mineral kingdom. That this is a mere supposition will appear by considering; first, that they do not know how this agent water is to operate in producing those effects; nor have they any direct proof of the fact which is alleged, from a very fallaceous analogy; and, secondly, that they cannot tell us where this operation is to be performed. They cannot say that it is in the earth above the level of the sea: for, the same appearances are found as deep as we can examine below that level; besides, we see that water has the opposite effect upon the surface of the earth, through which it percolates dissolving soluble substances, and thus resolving solid bodies in preparing soil for plants. If, again, it be below the level of the sea, that strata of the earth are supposed to be consolidated by the infiltration of that water which falls from the heavens; this cannot be allowed, so far as whatever of the earth is bibulous, in that place, must have been always full of water, consequently cannot admit of that supposed infiltration.

But allowing those suppositions to be true, there is nothing in them like a theory of the earth,—a theory that should bring the operations of the world into the regularity of ends and means, and, by generalizing these regular events, show us the operation of perfect intelligence forming a design; they are only an attempt to show how certain things, which we see, have happened without any perceivable design, or without any farther design than this particular effect which we perceive. If we believe that there is almighty power, and supreme wisdom employed for sustaining that beautiful system of plants and animals which is so interesting to us, we must certainly conclude, that the earth, on which this system of living things depends, has been constructed on principles that are adequate to the end proposed, and procure it a perfection which it is our business to explore. Therefore, a proper system of the earth should lead us to see that wise contraction, by which this earth is made to answer the purpose of its intention and to preserve itself from every accident by which the design of this living world might be frustrated as this world is an active scene. or a material machine moving in all its parts, we must see how this machine is so contrived, as either to have those parts to move without wearing and decay, or to have those parts, which are wasting and decaying, again repaired.

A rock or stone is not a subject that, of itself, may interest a philosopher to study; but, when he comes to see the necessity of those hard bodies, in the constitution of this earth, or for the permanency of the land on which we dwell, and when he finds that there are means wisely provided for the renovation of this necessary decaying part, as well as that of every other, he then, with pleasure, contemplates this manifestation of design, and thus connects the mineral system of this earth with that by which the heavenly bodies are made to move perpetually in their orbits. It is not, therefore, simply by seeing the concretion of mineral bodies that a philosopher is to be gratified in his his intellectual pursuit, but by the contemplation of that system in which the necessary resolution of this earth, while at present it serves the purpose of vegetation, or the fertility of our soil, is the very means employed in furnishing the materials of future land.

It is such a view as this that I have endeavoured to represent in the theory which I have given. I have there stated the present situation of things, by which we are led to perceive a former state; and, from that necessary progress of actual things, I have concluded a certain system according to which things will be changed, without any accident or error. It is by tracing this regular system in nature that a philosopher is to perceive the wisdom with which this world has been contrived; but, he must see that wisdom founded upon the aptitude of all the parts to fulfil the intention of the design; and that intention is to be deduced from the end which is known to be attained. Thus we are first to reason from effect to cause, in seeing the order of that which has already happened; and then, from those known causes, to reason forwards, so as to conceive that which is to come to pass in time. Such would be the philosophy of this earth, formed by the highest generalisation of phenomena, a generalisation which had required the particular investigation of inductive reasoning.

That no such theory as this, founded upon water as an agent operating in the changes of this earth, has yet appeared, will, I believe be easily allowed. With regard again to fire as an agent in the mineral operations of this earth, geologists have formed no consistent theory. They see volcanoes in all the quarters of the globe, and from those burning mountains, they conjecture other mountains have been formed. But a burning mountain is only a matter of fact; and, they have not on this formed any general principle, for establishing what may be called a theory of the earth. Those who have considered subterraneous fires as producing certain effects, neither know how these have been procured, nor do they see the proper purpose for which they are employed in the system of this world. In this case, the agent fire is only seen as a destructive element, in like manner as deluges of water have been attributed by others to changes which have happened in the natural state of things. These operations are seen only as the accidents of nature, and not as part of that design by which the earth, which is necessarily wasted in the operations of the world, is to be repaired.

So far from employing heat or subterraneous fire as an agent in the mineral operations of the earth, the volcanic philosophers do not even attempt to explain upon that principle the frequent nodules of calcareous, zeolite, and other spatose and agaty substances, in those basaltic bodies which they consider as lavas. Instead then of learning to see the operation of heat as a general principle of mineral consolidation and crystallization, the volcanic philosophers endeavour to explain those particular appearances, which they think inconsistent with fusion, by aqueous infiltration, no otherwise than other mineralists who do not admit the igneous origin of those basaltic bodies. Thus, that great agent, subterraneous heat, has never been employed by geologists, as a general principle in the theory of the earth; it has been only considered as an occasional circumstance, or as the accident of having certain mineral bodies, which are inflammable, kindled in the earth, without so much as seeing how that may be done.

This agent heat, then, is a new principle to be employed in forming a theory of the earth; a principle that must have been in the constitution of this globe, when contrived to subsist as a world, and to maintain a system of living bodies perpetuating their species. It is therefore necessary to connect this great mineral principle, subterraneous fire or heat, with the other operations of the world, in forming a general theory. For, whether we are to consider those great and constant explosions of mineral fire as a principal agent in the design, or only as a casual event depending upon circumstances which give occasion to an operation of such magnitude, here is an object that must surely have its place in every general theory of the earth.

In examining things which actually exist, and which have proceeded in a certain order, it is natural to look for that which had been first; man desires to know what had been the beginning of those things which now appear. But when, in forming a theory of the earth, a geologist shall indulge his fancy in framing, without evidence, that which had preceded the present order of things, he then either misleads himself, or writes a fable for the amusement of his reader. A theory of the earth, which has for object truth, can have no retrospect to that which had preceded the present order of this world; for, this order alone is what we have to reason upon; and to reason without data is nothing but delusion. A theory, therefore, which is limited to the actual constitution of this earth, cannot be allowed to proceed one step beyond the present order of things.

But, having surveyed the order of this living world, and having investigated the progress of this active scene of life, death and circulation, we find ample data on which to found a train of the most conclusive reasoning with regard to a general design. It is thus that there is to be perceived another system. of active things for the contemplation of our mind;—things which, though not immediately within our view, are not the less certain in being out of our sight; and things which must necessarily be comprehended in the theory of the earth, if we are to give stability to it as a world sustaining plants and animals. This is a mineral system, by which the decayed constitution of an earth, or fruitful surface of habitable land, may be continually renewed in proportion as it is wasted in the operations of this world.

It is in this mineral system that I have occasion to compare the explanations, which I give of certain natural appearances, with the theories or explanations which have been given by others, and which are generally received as the proper theory of those mineral operations. I am, therefore, to examine those different opinions, respecting the means employed by nature for producing particular appearances in the construction of our land, appearances which must be explained in some consistent mineral theory.

These appearances may all be comprehended under two heads, which are now to be mentioned, in order to see the importance of their explanation, or purpose which such an explanation is to serve in a theory of the earth. The first kind of these appearances is that of known bodies which we find composing part of the masses of our land, bodies whose natural history we know, as having existed in another state previous to the composition of this earth where they now are found; these are the relicts or parts of animal and vegetable bodies, and various stony substances broken and worn by attrition, all which had belonged to a former earth. By means of these known objects, we are to learn a great deal of the natural history of this earth; and, it is in tracing that history, from where we first perceive it, to the present state of things, that forms the subject of a geological and mineralogical theory of this earth. But, we are more especially enabled to trace those operations of the earth, by means of the second kind of appearances, which are now to be mentioned.

These again are the evident changes which those known bodies have undergone, and which have been induced upon such collected masses of which those bodies constitute a part. These changes are of three sorts; first, the solid state, and various degrees of it, in which we now find those masses which had been originally formed by the collection of loose and incoherent materials; secondly, the subsequent changes which have evidently happened to those consolidated masses which have been broken and displaced, and which have had other mineral substances introduced into those broken and disordered parts; and, lastly, that great change of situation which has happened to this compound mass formed originally at the bottom of the sea, a mass which, after being consolidated in the mineral region, is now situated in the atmosphere above the surface of the sea.

In this manner we are led to the system of the world, or theory of the earth in general; for, that great change of situation, which our land has undergone, cannot be considered as the work of accident, or any other than an essential part in the system of this world. It is therefore a proper view of the necessary connection and mutual dependence of all those different systems of changing things that forms the theory of this earth as a world, or as that active part of nature which the philosophy of this earth has to explore. The animal system is the first or last of these; next comes the vegetable system, on which the life of animals depends; then comes the system of this earth, composed of atmosphere, sea, and land, and comprehending the various chemical, mechanical, and meteorologically operations which take place upon that surface where vegetation must proceed; and, lastly, we have the mineral system to contemplate, a system in which the wasting surface of the earth is employed in laying the foundation of future land within the sea, and a system in which the mineral operations are employed in concocting that future land.

Now, such must surely be the theory of this earth, if the land is continually wasting in the operations of this world; for, to acknowledge the perfection of those systems of plants and animals perpetuating their species, and to suppose the system of this earth on which they must depend, to be imperfect, and in time to perish, would be to reason inconsistently or absurdly. This is the view of nature that I would wish philosophers to take; but, there are certain prejudices of education or prepossession of opinion among them to be overcome, before they can be brought to see those fundamental propositions,—the wasting of the land, and the necessity of its renovation by the co-operation of the mineral system. Let us then consider how men of science, in examining the mineral state of things, and reasoning from those appearances by which we are to learn the physiology of this earth, have misled themselves with regard to physical causes, and formed certain mineralogical and geological theories, by which their judgment is so perverted, in examining nature, as to exclude them from the proper means of correcting their first erroneous notions, or render them blind to the clearest evidence of any other theory that is proposed.

When men of science reason upon subjects where the ideas are distinct and definite, with terms appropriated to the ideas, they come to conclusions in which there is no difference of opinion. It is otherwise in physical subjects, where things are to be assimilated, in being properly compared; there, things are not always compared in similar and equal circumstances or conditions; and there, philosophers often draw conclusions beyond the analogy of the things compared, and thus judge without data. When, for example, they would form the physical induction, with regard to the effect of fire or water upon certain substances in the mineral regions, from the analogy of such events as may be observed upon the surface of the earth, they are apt to judge of things acting under different circumstances or conditions, consequently not producing similar effects; in which case, they are judging without reason, that is, instead of inductive reasoning from actual data or physical truth, they are forming data to themselves purely by supposition, consequently, so far as these, imagined data may be wrong, the physical conclusion, of these philosophers may be erroneous.

It is thus that philosophers have judged, with regard to the effects of fire and water upon mineral substances below the bottom of the sea, from what their chemistry had taught them to believe concerning bodies exposed to those agents in the atmosphere or on the surface of the earth. If in those two cases the circumstances were the same, or similar, consequently the conditions of the action not changed, then, the inductive reasoning, which they employ in that comparison, would be just; but, so far as it is evidently otherwise, to have employed that inductive conclusion for the explanation of mineral appearances, without having reason to believe that those changed circumstances of the case should not make any difference in the action or effect, is plainly to have transgressed the rules of scientific reasoning; consequently, instead of being a proper physical conclusion, it is only that imperfect reasoning of the vulgar which, by comparing things not properly analysed or distinguished, is so subject to be erroneous. This vague reasoning, therefore, cannot be admitted as a part of any geological or mineral theory. Now I here maintain, that philosophers have judged in no other manner than by this false analogy, when they conclude that water is the agent by which mineral concretions have been formed. But it will be proper to state more particularly the case of that misunderstanding among mineral philosophers.

In forming a geological theory, the general construction of this earth, and the materials of which it is composed, are such visible objects, and so evident to those who will take the pains to examine nature, that here is a subject in which there cannot be any doubt or difference of opinion. Neither can there be any dispute concerning the place and situation of mass when it was first formed or composed; for, this is clearly proved, from every concomitant circumstance, to have been at the bottom of the sea. The only question in this case, that can be made, is, How that mass comes now to be a solid body, and above the surface of the sea in which it had been formed?

With regard to the last, the opinions of philosophers have been so dissonant, so vague, and so unreasonable, as to draw to no conclusion. Some suppose the land to be discovered by the gradual retreat of the ocean, without proposing to explain to us from whence had come the known materials of a former earth, which compose the highest summits of the mountains in the highest continents of the earth. Others suppose the whole of a former earth to have subsided below the bottom even of the present sea, and together with it all the water of the former sea, from above the summits of the present mountains, which had then been at the bottom of the former sea. The placing of the bottom of the sea, or any part of it, in the atmosphere so as to be dry land, is no doubt a great operation to be performed, and a difficult task to be explained; but this is only an argument the more for philosophers to agree in adopting the most reasonable means.

But though philosophers differ so widely in that point, this is not the case with regard to the concretion of mineral bodies; here mineralists seem to be almost all of one mind, at the same time without any reason, at least, without any other reason than that false analogy which they have inconsiderately formed from the operations of the surface of this earth. This great misunderstanding of mineralists has such an extensive and baneful effect in the judging of geological theories, that it will be proper here to explain how that has happened, and to show the necessity of correcting that erroneous principle before any just opinion can be formed upon the subject.

Fire and water are two great agents in the system of this earth; it is therefore most natural to look for the operation of those agents in the changes which are made on bodies in the mineral regions; and as the consolidated state of those bodies, which had been collected at the bottom of the sea, may have been supposed to be induced either by fusion, or by the concretion from a solution, we are to consider how far natural appearance lead to the conclusion of the one or other of those two different operations. Here, no doubt, we are to reason analogically from the known power and effects of those great agents; but, we must take care not to reason from a false analogy, by misunderstanding the circumstances of the case, or not attending to the necessary conditions in which those agents act.—We must not conclude that fire cannot burn in the mineral regions because our fires require the ventilation of the atmosphere; for, besides the actual exigence of mineral fire being a notorious matter of fact, we know that much more powerful means may be employed by nature, for that mineral purpose of exciting heat, than those which we practise.—We must not conclude that mineral marble is formed in the same manner as we see a similar stony substance produced upon the surface of the earth, unless we should have reason to suppose the analogy to be complete. But, this is the very error into which mineral philosophers have fallen; and this is the subject which I am now to endeavour to illustrate.

The manner in which those philosophers have deceived themselves when reasoning upon the subject of mineral concretion, is this: They see, that by means of water a stony substance is produced; and, this stony body so much resembles mineral marble as to be hardly distinguishable in certain cases. These mineral philosophers then, reasoning in the manner of the vulgar, or without analysing the subject to its principle, naturally attribute the formation of the mineral marble to a cause of the same sort; and, the mineral marble being found so intimately connected with all other mineral bodies, we must necessarily conclude, in reasoning according to the soundest principles, that all those different substances had been concreted in the same manner. Thus, having once departed one step from the path of just investigation, our physical science is necessarily bewildered in the labyrinth of error. Let us then, in re-examining our data, point out where lies that first devious step which had been impregnated with fixed air, or carbonic acid gas, (as it is called), dissolves a certain portion of mild calcareous earth or marble; consequently such acidulated water, that is, water impregnated with this gas, will, by filtrating through calcareous substances, become saturated with that solution of marble; and, this solution is what is called a petrifying water. When this solution is exposed to the action of the atmosphere, the acid gas, by means of which the stony substance is dissolved, evaporates from the solution, in having a stronger attraction for the atmospheric air; it is then that the marble, or calcareous substance, concretes and crystallises, separating from the water in a sparry state, and forming a very solid stone by the successive accretion from the solution, as it comes to be exposed to the influence of the atmosphere in flowing over the accumulating body. Here is the source of their delusion; for, they do not distinguish properly the case of this solution of a stony substance concreting by means of the separation of its solvent, and the case of such a solution being in a place where that necessary condition cannot be supposed to exist; such as, e.g., the interstices among the particles of sand, clay, etc. deposited at the bottom of the sea, and accumulated in immense stratified masses.

No example can better illustrate how pernicious it is to science to have admitted a false principle, on which a chain of reasoning is to proceed in forming a theory. Mineral philosophers have founded their theory upon that deceitful analogy, which they had concluded between the stalactical concretions of petrifying waters and the marble formed in the mineral regions; thus, blinded by prejudice, they shut the door against the clearest evidence; and it is most difficult to make them see the error of their principle. But this is not to be wondered at, when we consider how few among philosophising men remount to the first principles of their theory; and, unless they shall thus remount to that first step, in which the concreting operation of a dissolved stony substance is supposed to take place without the necessary conditions for the petrifying operation, it is impossible to be convinced that their theory, thus formed with regard to mineral concretion, is merely supposition, and has no foundation in matter of fact from whence it should proceed.

But this is not all; for, even supposing their theory to be well founded and just, it is plainly contradicted by natural appearances. According to that theory of aqueous consolidation, all the stratified bodies, of which this earth in general consists, should be found in the natural order of their regular formation; but, instead of this, they are found every where disturbed in that order more or less; in many places this order and regularity is so disturbed as hardly to be acknowledged; in most places we find those stratified bodies broken, dislocated, and contorted, and this aqueous theory of mineralists has neither the means for attaining that end, were it required in their theory, nor have they any such purpose in their theory, were that end attainable by the means which they employ. Thus blinded by the prejudice of a false analogy, they do not even endeavour to gratify the human understanding (which naturally goes in quest of wisdom and design) by forming a hypothetical or specious theory of the mineral system; and they only amuse themselves with the supposition of an unknown operation of water for the explanation of their cabinet specimens, a supposition altogether ineffectual for the purpose of forming a habitable earth, and a supposition which is certainly contradicted by every natural appearance.

Thus, in examining geological and mineralogical theories, I am laid under the disagreeable necessity of pointing out the errors of physical principles which are assumed, the prejudices of theoretical opinions which have been received, and the misconceived notions which philosophers entertain with regard to the system of nature, in which may be perceived no ineffectual operation, nor any destructive intention, but the wise and benevolent purpose of preserving the present order of this world. But, though thus misled with regard to the cause of things, naturalists are every where making interesting observations in the mineral kingdom, I shall therefore avail myself of that instructive information, for the confirmation of my theory.

It may now be proper to consider what must be required, in order to have a geological and mineral theory established upon scientific principles, or on such grounds as must give conviction to those who will examine the subject; for, unless we may clearly see that there are means for attaining that desirable end, few philosophers will be persuaded to pursue this branch of knowledge.

A theory is nothing but the generalization of particular facts; and, in a theory of the earth, those facts must be taken from the observations of natural history. Nature is considered as absolutely true; no error or contradiction can be found in nature. For, if such contradiction were truly found, if the stone, for example, which fell to day were to rise again to-morrow, there would be an end of natural philosophy, our principles would fail, and we would no longer investigate the rules of nature from our observations.

Every natural appearance, therefore, which is explained, i.e. which is made to come into the order of things that happen, must so far confirm the theory to which it then belongs. But is it necessary, that every particular appearance, among minerals, should be thus explained in a general theory of the earth? And, is any appearance, which is not explained by it, to be considered as sufficient to discredit or confute a theory which corresponded with every other appearance? Here is a question which it would require some accuracy to resolve.

If we knew all the powers of nature, and all the different conditions in which those powers may have their action varied, that is to say, if we were acquainted with every physical cause, then every natural effect, or all appearances upon the surface of this earth, might be explained in a theory that were just. But, seeing that this is far from being the case, and that there may be many causes of which we are as yet ignorant, as well as certain conditions in which the known action of powers may be varied, it must be evident, that a theory of the earth is not to be confuted by this argument alone, That there are, among natural bodies, certain appearances which are not explained by the theory. We must admit, that, not having all the data which natural philosophy requires, we cannot pretend to explain every thing which appears; and that our theories, which necessarily are imperfect, are not to be considered as erroneous when not explaining every thing which is in nature, but only when they are found contrary to or inconsistent with the laws of nature, which are known, and with which the case in question may be properly compared.

But we may have different theories to compare with nature; and, in that case, the question is not, How far any of those theories should explain all natural appearances? but, How far any one particular theory might explain a phenomenon better than another? In this case of comparison, it will be evident, that if one theory explains natural appearances, then the opposite to that theory cannot be supposed to explain the same appearances. If for example, granite, porphyry, or basaltes, should be found naturally formed by fusion, the formation of those stones could not be supposed in any case as formed by water, although it could not be demonstrated that water is incapable of forming those mineral productions.

In like manner, if those three bodies were proved to have been actually formed by water alone, then, in other cases where we should have no proof, they could not be supposed as having been formed by fire or fusion. It must be evident, that an equal degree of proof of those two different propositions would leave our judgment in suspence, unless that proof were perfect, in which case, we would have two different causes producing similar effects. But, if we shall have a sufficient proof upon the one side, and only a presumptive proof or probability upon the other, we must reject that probability or presumption, when opposed by a proof, although that proof were only an induction by reasoning from similar effects as following similar causes. A fortiori, if there be on one side a fair induction, without the least suspicion of error, and on the other nothing but a mere presumption founded upon a distant analogy, which could not even properly apply, then, the inductive proof would be as satisfactory as if there had not been any supposition on the opposite side.

So far as a theory is formed in the generalization of natural appearances, that theory must be just, although it may not be perfect, as having comprehended every appearance; that is to say, a theory is not perfect until it be founded upon every natural appearance; in which case, those appearances will be explained by the theory. The theory of gravitation, though no ways doubtful, was not so perfect before the shape of this globe had been determined by actual measurement, and before the direction of the plummet had been tried upon Shihallion, as after those observations had been made. But a theory which should be merely hypothetical, or founded upon a few appearances, can only be received as a theory, after it has been found to correspond properly with nature; it would then be held a proper explanation of those natural appearances with which it corresponded; and, the more of those phenomena that were thus explained by the theory, the more would that, which had been first conjectural, be converted into a theory legitimately founded upon natural appearances.

Matter of fact is that upon which science proceeds, by generalization, to form theory, for the purpose of philosophy, or the knowledge of all natural causes; and it is by the companion of these matters of fact with any theory, that such a theory will be tried. But, in judging of matter of fact, let us be cautious of deceiving ourselves, by substituting speculative reasoning in place of actual events.

Nature, as the subject of our observation, consists of two sorts of objects; for, things are either active, when we perceive change to take place in consequence of such action, or they are quiescent, when we perceive no change to take place. Now, it is evident, that in judging of the active powers of nature from the quiescent objects of our information, we are liable to error, in misinterpreting the objects which we see; we thus form to ourselves false or erroneous opinion concerning the general laws of action, and the powers of nature. In comparing, therefore, generalised facts, or theory, with particular observations, there is required the greatest care, neither, on the one hand, to strain the appearances, so as to bring in to the theory a fact belonging to another class of things; nor, on the other, to condemn a proper theory, merely because that theory has not been extended to the explanation of every natural appearance.

But, besides the misinterpretation of matters of fact, we are also to guard against the misrepresentation of natural appearances. Whether warped by the prejudice of partial and erroneous theory, or deceived by the inaccuracy of superficial observation, naturalists are apt to see things in an improper light, and thus to reason from principles which cannot be admitted, and, which often lead to false conclusions. A naturalist, for example, comes to examine a cavity in the mines, he there finds water dropping down all around him, and he sees the cavity all hung with siliceous crystals; he then concludes, without hesitation, that here is to be perceived cause and effect, or that he actually sees the formation of those crystallizations from the operation of water. It is thus that I have been told by men of great mineral knowledge, men who must have had the best education upon that subject of mineralogy, and who have the superintendance of great mineral concerns in Germany, that they had actually seen nature at work in that operation of forming rock-crystal;—they saw what I have now described; they could see no more; but, they saw what had convinced them of that which, there is every reason to believe, never happened. With regard to my theory, I wish for the most rigorous examination; and do not ask for any indulgence whatever, whether with regard to the principles on which the theory is built, or for the application of the theory to the explanation of natural appearances. But, let not geologists judge my theory by their imperfect notions of nature, or by those narrow views which they take of the present state of things;—let not mineralogists condemn my theory, for no other reason but because it does not correspond with their false principles, and those gratuitous suppositions by which they had been pleased to explain to themselves every thing before. First let them look into their own theory, and correct that erroneous principle, with regard to the action of water, or the assumption of unknown causes, upon which they have reasoned in forming their vague notions of the mineral region, before they can be properly qualified to examine, impartially, a theory which employs another principle. Every thing which has come under my observation shall be, as far as I can, faithfully related; nor shall I withhold those which neither the present theory, nor any other that I am acquainted with, can, I think, explain.

Appearances cannot well be described except in relation to some theory or general arrangement of the subject; because the particular detail, of every part in a complicated appearance, would be endless and insignificant. When, however, any question in a theory depends upon the nature of an appearance, we cannot be too particular in describing that by which the question is to be decided. But though it be sometimes proper to be minute in a particular, it is always, and above all things, necessary to be distinct; and not to confound together things which are of different natures. For, though it be by finding similarity, in things which at first sight may seem different, that science is promoted and philosophy attained, yet, we must have a distinct view of those things which are to be assimilated; and surely the lowest state of knowledge in any subject, is the not distinguishing things which, though not to common observation different, are not truly the same.

To confound, for example one stone with another, because they were both hard, friable, and heavy, would be to describe, with the superficial views of vulgar observation; whereas science specifies the weight and hardness, and thus accurately distinguishes the stone.

Before naturalists had learned to distinguish what they saw, and to describe, in known terms, those natural appearances, a theorist must have generalised only from his proper observation. This has been my case. When I first conceived my theory, few naturalists could write intelligibly upon the subject; but that is long ago, and things are much altered since; now there are most enlightened men making observations, and communicating natural knowledge. I have the satisfaction, almost every day, to compare the theory, which I had formed from my proper observations, with the actual state of things in almost every quarter of the globe.

Whether, therefore, we mean to try a theory by its application to such phenomena as are well understood, or to learn something from the application of particular phenomena to a well established theory, we shall always find it interesting to have appearances described; particularly such as may be referred to some general rule, as circumscribing it to certain conditions, or as finding rule in rule, that is to say, discovering those particular conditions in which the general laws of action may be affected.

Instead, for example, of the rule which we find in the application of heat for the fusion and evaporation of mineral substances upon the surface of this earth, we may find it necessary to consider the effect which changed circumstances produce in the mineral regions, and occasion a change of that rule of action which we have learned from experience, when melting and evaporating those substances in the atmosphere or on the surface of the earth.

It is in this manner that a theory, which was formed by the generalization of particular facts, comes to be a source of information, by explaining to us certain appearances which otherwise we could not understand. Thus, it was not the appearance of the tides that taught the theory of gravitation; it was the theory of gravitation that made us understand the appearance of the tides. In like manner, the law of gravitation, which was demonstrated from the motion of the moon in her orbit round this earth, when applied to the paths of comets, explained that appearance. Our theory, of a central fire, has been formed upon the consolidation of the strata of this earth; but this theory is to be applied for the explanation of various different appearances. In this manner, two different purposes will be served; the trying of the theory by its application to phenomena; and the explanation of phenomena by the principles laid open in the theory.

I may repeat it; a theory of the earth must ultimately depend upon matter of fact or particular observation; but those observations must be distinct, and those distinguished things must be generalised. We have just now given for an example, a distinction among stones, in knowing them by their sensible qualities. But, besides distinguishing those objects, we are also to inquire into the origin and cause of those things which are distinguished. Here, again, we take into our aid the chemical as well as the mechanical properties of these several things; and hence learn to know on what their natural form and constitution may depend. Having thus attained the natural philosophy of stones, we next inquire into the place and application of those things in nature; and in this manner we acquire some knowledge with regard to the natural constitution of this earth. We find this earth composed of known things; it is therefore the operations, required in these compositions, which form the natural philosophy of this earth, considered as a body of solid land. But, the solid land is only one part of the globe; therefore, the philosophy of the globe proceeds still farther by knowing the constitution of this planetary body, as consisting of different parts united for a purpose, which is that of a world.

The general theory of this earth as a world, will thus appear to be a complex thing, which however founded upon simple principles, contains many subjects of discussion, and requires attention to a variety of particulars. For, not only the great features of this earth are to be explained by the theory, but also the most minute appearance, such as are to be found, even with microscopic observation, in every particular part.

Thus the nature, constitution, and cause of every particular appearance in the construction of this earth, are to be investigated in a geological theory, as well as that general constitution of the world in which all the particular parts are to be employed for a purpose.

If the subject here examined shall be found properly explained, there will remain little doubt with regard to the justness of the theory, which will then be applicable to other appearances that may occur; although every appearance is not to be explained, in a manner equally satisfactory, by any theory which is not perfect.

The first subject to be examined is the modern theory of primitive mountains. I have written several chapters upon that subject, having successively acquired more light in this interesting part of the theory, by observations of my own in several places of this country, as well as from the natural history of other countries. I shall give these nearly in the order in which they occurred, or had been written.

CHAP. IV.

The Supposition of Primitive Mountains refuted.

In the theory now given, the earth has been represented as a composition of different materials, which had existed in another form, and as the effect of natural operations; therefore, however various may be found the structure of our earth, and however dissimilar some parts of its composition may be in comparison with others, no part should be considered as original, in relation to the globe, or as primitive, in relation to second causes, i.e. physical operations by which those parts should have been formed. But it is pretended by naturalists, that there are certain primitive mountains in the earth, bodies which have had another origin than that of the general strata of the globe and subsequent masses; an origin, therefore, which cannot be considered as having been produced from natural operations, or as effected in the course of known causes. Now, if it can be made to appear, that there is no solid ground for this distinction; and if it can be shown, that there is truly no mineral body in this earth which may not have been produced by operations natural to the globe, we should thus procure a certain confirmation of the doctrine. This also will be the more interesting, in being deduced from a part of natural appearances, which seemed to be inconsistent with the theory.

Certain masses or mountains of granite, are the only bodies of this earth which have apparently a certain pretension to this species of originality. These, therefore, must be now the subject of our examination.

Granite, considered by itself, does not appear to have any claim to originality in its nature. It is composed of bodies which are capable of being analysed; and these are then found to be compositions of different substances, which are also sometimes variously proportioned. The feldspar and the mica, for example, as well as the schorl, are found variously coloured in different granites, and coloured in various proportions. Besides the variety in the composition, or chemical mixture of the different bodies which compose granite, this rock admits of a great diversity, from the variety of its mechanical mixture, or from the different species of bodies which are its constituent parts. M. de Saussure, who has examined this subject perhaps more than any other person, and who has had the very best opportunities for this purpose, says, that this composition may be found in all the different combinations which may be produced by every possible composition of 7 or 8 different kinds of stone, (page 108, Voyage dans les Alpes, etc.). Neither does this fill up the measure of its variety; for, another source of change is found in the grain of this rock stone; I have a specimen of this variety from the size almost of sand to that of some inches.

Were granite, therefore, to be supposed as in the original state of its creation, nature would be considered as having operated in an indefinite diversity of ways, without that order and wisdom which we find in all her works; for here would be change without a principle, and variety without a purpose. There is no reason, however, to suppose granite original, more than any other composite rock, although we may be ignorant of the particular process in which it is formed, and although, comparatively in relation to certain other rocks, granite, or certain masses of this composition, may be found of a more ancient date.

If granite be truly stratified, and those strata connected with the other strata of the earth, it can have no claim to originality; and the idea of primitive mountains, of late so much employed by natural philosophers, must vanish, in a more extensive view of the operations of the globe; but it is certain that granite, or a species of the same kind of stone, is thus found stratified. It is the granit feuilletée of M. de Saussure, and, if I mistake not, what is called gneis by the Germans. We have it also in our north alpine country of Scotland; of this I have specimens, but have not seen it in its place.

Granite being thus found stratified, the masses of this stone cannot be allowed to have any right of priority over the schistus, its companion in the alpine countries, although M. de Saussure, whose authority I would revere, has given it for the following reason; that it is found the most centrical in the chains of high mountains, or in alpine countries. Now, supposing this fact to be general, as he has found it in the Alps, no argument for the priority of those masses can be founded either upon the height or the situation of those granite mountains; for the height of the mountain depends upon the solidity and strength of the stone. Now though it is not to be here maintained that granite is the most durable of those alpine rocks, yet as a mountain, either granite in general, or in particular, certain species of it, may be esteemed such, consequently, this massy stone, remaining highest in the mountainous region, will naturally be considered as the centre, and according to this rule, as having the pre-eminence in point of seniority.

The rock which stands in competition with granite for the title of primitive in the order of mountains, is that micaceous stratified stone which is formed chiefly of quartz, but which admits of great variety like the granite. The difference between those two bodies does not consist in the materials of which they are composed, for, in their varieties, they may be in this respect the same, but in a certain regularity of composition, in this alpine stone, which evidently arises from stratification or subsidence in water.

If we shall thus consider all the varieties of this alpine stone as being of one kind, and call it granite, then we shall distinguish in this body two different species, from whence perhaps some interesting conclusion may be formed with regard to the operations of the globe. These two species are, first, granite regular in its composition, or stratified in its construction; and, secondly, granite in mass, or irregular in its construction. Let us now endeavour to make use of these generalizations and distinctions.

In examining the great diversity of our whinstone, trap, or basaltes, it is found at last to granulate into granite; at the same time those two different species of rock-stone may be distinguished. A perfect granite has not in its composition necessarily any argillaceous earth, farther than may be in the natural constitution of its distinct parts; whereas, a perfect basalt may have abundance of this substance, without any quartz or any siliceous body. A perfect granite, is, therefore, an extremely hard stone, having quartz and feldspar for its basis; but a perfect whin or basaltes may be extremely soft, so as to cut easily with a knife. In like manner granite is a composition which graduates into porphyry; but porphyry is only whinstone of a harder species. Therefore, though perfectly distinct, those three things graduate into each other, and may be considered as the same.

Granite and whinstone, or basaltes, though distinct compositions, thus graduating into each other; and whinstone, as well as porphyry, being without doubt a species of lava, we may consider the granite which is found in mass without stratification, in like manner as we do the masses of whinstone, basaltes, or Swedish trap, as having flowed in the bowels of the earth, and thus been produced by the chance of place, without any proper form of its own, or in an irregular shape and construction. In this manner would be explained the irregular shape or structure of those granite masses; and thus great light would be thrown upon the waved structure of the stratified alpine stone, which, though it has not been made to flow, has been brought to a great degree of softness, so as to have the original straight lines of its stratification changed to those undulated or waving lines which are in some cases extremely much incurvated.

It remains only to confirm this reasoning, upon our principles, by bringing actual observation to its support; and this we shall do from two of the best authorities. The Chevalier de Dolomieu, in describing the volcanic productions of Etna, mentions a lava which had flowed from that mountain, and which may be considered as a granite. But M. de Saussure has put this matter out of doubt by describing most accurately what he had seen both in the Alps and at the city of Lyons. These are veins of granite which have flowed from the contiguous mass into the stratified stone, and leave no doubt with regard to this proposition, that the granite had flowed in form of subterranean lava, although M. de Saussure has drawn a very different conclusion from this appearance. I have also a specimen from this country of a vein of granite in a granite stone, the vein being of a smaller grain than that of the rock which it traverses.[²⁰]

Footnote 20:[ (return) ] This is what I had wrote upon, the subject of granite, before I had acquired such ample testimony from my own observations upon that species of rock. I have given some notice, in the 3d vol. of the Transactions of the Edinburgh R.S. concerning the general result of those observations, which will be given particularly in the course of this work.

It will thus appear, that the doctrine which of late has prevailed, of primitive mountains, or something which should be considered as original in the construction of this earth, must be given up as a false view of nature, which has formed the granite upon the same principle with that of any other consolidated stratum; so far as the collection of different materials, and the subsequent fusion of the compound mass, are necessary operations in the preparation of all the solid masses of the earth. Whatever operations of the globe, therefore, may be concluded from the composition of granite masses, as well as of the alpine strata, these must be considered as giving us information with regard to the natural history of this earth; and they will be considered as important, in proportion as they disclose to us truths, which from other strata might not be so evident, or at all made known.

Let us now examine the arguments, which, may be employed in favour of that supposition of primitive mountains.

The observations, on which naturalists have founded that opinion of originality in some of the component parts of our earth, are these; first, They observe certain great masses of granite in which stratification is not to be perceived; this then they say is an original mass, and it is not to be derived from any natural operation of the globe; secondly, They observe considerable tracts of the earth composed of matter in the order of stratification as to its general composition, but not as to its particular position, the vertical position here prevailing, instead of the horizontal which is proper to strata formed in water; this, therefore, they also term primitive, and suppose it to be from another origin than that of the subsidence of materials moved in the waters of the globe; lastly, They observe both strata and masses of calcareous matter in which they cannot distinguish any marine body as is usual in other strata of the same substance; and these calcareous masses being generally connected with their primitive mountains, they have also included these collections of calcareous matter, in which marine bodies are not observed, among the primitive parts which they suppose to be the original construction of this globe.

It may be proper to see the description of a calcareous alpine mountain. M. de Saussure gives us the following observations concerning a mountain of this kind in the middle of the Alps, where the water divides in running different ways towards the sea. It is in describing the passage of the Bon-Homme, (Tom. 2. V. dans les Alpes).

"§ 759. Sur la droite ou au couchant de ces rochers, on voit une montagne calcaire étonnante dans ce genre par la hardiesse avec laquelle elle élève contre le ciel ses cimes aigues et tranchantes, taillées à angles vifs dans le costume des hautes cimes de granit. Elle est pourtant bien sûrement calcaire, je l'ai observée de près, et on rencontre sur cette route les blocs qui s'en détachent.

"Cette pierre porte les caractères des calcaires les plus anciennes; sa couleur est grise, son grain assez fin, on n'y apperçoit aucun vestige de corps organisés; ses couches sont peu épaisses, ondées et coupées fréquemment par des fentes parallèles entr'elles et perpendiculaires à leurs plans. On trouve aussi parmi ces fragmens des brèches calcaires grises."

Here is a mountain which will rank with the most primitive of the earth; But why? only because it is extremely consolidated without any mark of organised body. Had there been in this mountain but one single shell, we should not then have scrupled to conclude that the origin of this lofty mountain had been the same with every marble or limestone in the earth. But though, from the structure of this stone, there is no mark of its having been formed immediately of the calcareous parts of animals, there is every mark of those calcareous strata having been formed like other marbles by deposit in the waters of the globe.

These two things are also homologated by the equal or perfect consolidation of their substance; for, as it is to be proved that all stratified marbles have been consolidated by the fusion of their substance, we must attribute the same consolidating cause to those alpine masses; the frequent veins that divide those calcareous strata which M. de Saussure has here described, also prove the nature of the consolidating cause, (see Chap. 1. page 111.).

This mountain, considered by itself, may perhaps afford no data by which a naturalist might read the circumstances of its origin. But, Is a theory of the earth to be formed upon such a negative observation? and, Is there any particular in this mountain, that may not be shown in others of which the origin is not in any degree doubtful?

It is not to be disputed, that there are parts of the solid body of our earth which may be considered as primary or prior, compared with others that are posterior, in relation to the time of their formation, and much less changed with regard to the state in which they had been originally formed:—But it is here denied, that there are any parts of the earth which do not appear to have had the same origin with all the rest, so far as this consists in the collection of materials deposited at the bottom of the waters[²¹]; for there is no solid mass of land that may not be traced to this origin, either from its composition, or from its local connection with other masses, the nature of which in this respect are known. We have already given examples of this from sufficient authority. The evidence, therefore, of those primary masses being original in relation to the natural operations of the globe, is reduced to this assertion, that there are no vestiges of organised bodies to be found in those primary masses. Let us now examine how far this testimony for the originality of those masses is to be admitted in fact and sound reasoning.

Footnote 21:[ (return) ] There are no collection of those alpine masses in which may not be found in some of them sand, mica, and gravel; but these materials prove the existence of an earth, on which those fragments of greater masses had been formed, and more or less worn by attrition.

The matter in question at present is this, that there are certain tracts of countries in which no vestige of organised bodies are found; now, let us suppose the fact to be true or well grounded, Can we conclude from this that there had been originally no organised bodies in the composition of those masses?—Such a conclusion could only be formed in making a supposition, that every organised body deposited in a mass of matter, whether homogeneous or heterogeneous, should be preserved without change, while the collected mass, in which it had been deposited, changes as much as possible by the operation both of fire and water. But this supposition is erroneous, and cannot be admitted; and the study of marbles will demonstrate this truth, that the calcareous relics of organised bodies are changed, in the consolidating operations of the globe, in every degree, from the smallest alteration to the greatest, when they become indistinguishable any farther to our sight.

Therefore, from the supposition of no appearance of marine bodies in the pretended primitive masses, there is no sufficient evidence or reason to conclude, that those masses have not had a marine origin; because, the traces of organised bodies may be obliterated by the many subsequent operations of the mineral region; and which operations, the present state of those masses certify beyond dispute.

We are now to examine the fact, how far the ground on which that false reasoning had been founded is strictly true.

In the first place, then, it must be considered, that the alleged fact is nothing but a negative assertion, importing that no mark of organised bodies had been observed, in certain stones and strata which some naturalists have examined with that view. But, though many naturalists have looked for them without success, it does not follow that such marks may not be found; it indeed proves that such a task is difficult, and the success of it, to a particular, most precarious; accident, however, may bring about what the greatest industry has not been able to attain. Secondly, there is good reason to believe that this asserted negation is not absolutely true; for I have in my possession what I consider as proof of the contrary; I found it in Wales, and I think it is in what may be considered as primitive mountains;—it is the mark of shells in a stone of that kind.

Thus, I had formed my opinion with regard to this alleged fact, long before I had seen any description either of the Alps or Pyrennean mountains; and now I have no reason to change that opinion. It may indeed be alleged, that the strata of marble or limestone, containing marine bodies found in those mountains, are secondary strata, and not the primitive. To this I can give no reply, as the descriptions given of those strata do not enable me to decide this point.

At the village of Mat, under the Mont Blatten for example, there is a quarry of schistus or black slate, in which are often found the print and the bones of fishes. (Discours sur l'Histoire Naturelle de la Suisse, page 225.). If this may be considered as an alpine or primitive schistus, it would be decisive of the question: But it would require to have it well ascertained that this schistus is truly one of those which are esteemed primitive, or that it is properly connected with them.

But though I cannot find in those interesting descriptions which we now have got, any one which is demonstrative of this truth, that calcareous marine objects are found in the primitive strata, this is not the case with regard to another object equally important in deciding this question, Whether the primitive strata are found containing the marks of organised bodies?

M. de Dellancourt, in his Observations Minéralogiques, Journal de Physique Juillet 1786, in describing the mountains of Dauphiné, gives us the following fact with regard to those alpine vertical strata.

"La pierre constituante de la montagne d'Oris est en général le Kneifs ou la roche feuilletée mica et quartz à couches plus ou moins ferrées quelquefois le schorl en roche pénétré de stéatite. Les couches varient infiniment quant à leur direction et à leur inclinaisons. Cette montagne est cultivée et riche dans certain cantons, surtout autour du village d'Oris, mais elle est très-escarpée dans beaucoup d'autres. Entre le village d'Oris et celui du Tresnay est une espèce de combe assez creuse formée par la chute des eaux des cimes supérieures des rochers. Cette combe offre beaucoup de schiste dont les couches font ou très-inclinées ou perpendiculaires. Entre ces couches il s'en est trouvé de plus noires que les autres et capable de brûler, mais difficilement. Les habitans ont extrait beaucoup de cette matière terreuse, et lui ont donné le nom de charbon de terre. Ils viennent même à bout de la faire brûler, et de s'en servir l'hiver en la mêlant avec du bois. Ce schiste noir particulier m'a paru exister principalement dans les endroits ou les eaux se sont infiltrées entre les couches perpendiculaires, et y ont entraîné diverse matières, et sur-tout des débris de végétaux que j'ai encore retrouvés à demi-noirs, pulvérulens et comme dans un état charbonneux."

This formation of coal, by the infiltration of water and carrying in of vegetable bodies, certainly cannot be admitted of; consequently, from this description, there would seem to be strata of coal alternated with the alpine schisti. But the formation of mineral coal requires vegetable matter to have been deposited along with those earthy substances, at the bottom of the sea. The production of vegetable bodies, again, requires the constitution of sea and land, and the system of a living world, sustaining plants at least, if not animals.

In this natural history of the alpine schisti, therefore, we have a most interesting fact, an example which is extremely rare. Seldom are calcareous organised bodies found among those alpine strata, but still more rarely, I believe, are the marks of vegetable bodies having contributed in the formation of those masses. But however rare this example, it is equally decisive of the question, Whether the alpine schisti have had a similar origin as the other strata of the globe, in which are found abundance of animal and vegetable bodies, or their relics? and we are authorised to say, that since those perfect alpine strata of Dauphiné have had that origin, all the alpine schisti of the globe have been originally formed in a similar manner. But to put this matter out of doubt:

In this summer 1788, coming from the Isle of Man, Mr Clerk and I travelled through the alpine schistus country of Cumberland and Westmoreland. We found a limestone quarry upon the banks of Windermere, near the Low-wood Inn. I examined this limestone closely, but despaired of finding any vestige of organised body. The strata of limestone seem to graduate into the slate or schistus strata, between which the calcareous are placed. Fortunately, however, I at last found a fragment in which I thought to perceive the works of organised bodies in a sparry state; I told Mr Clerk so, and our landlord Mr Wright, who had accompanied us. I have brought home this specimen, which I have now ground and polished; and now it is most evidently full of fragments of entrochi. Mr Wright then told me he had seen evident impressions of marine objects, as I understood from the description, in the slate of those mountains; and he was to send me specimens so soon as he could procure them.

Here is one specimen which at once overturns all the speculations formed upon that negative proposition. The schistus mountains of Cumberland were, in this respect, as perfect primitive mountains as any upon the earth, before this observation; now they have no claim upon that score, no more than any limestone formed of shells.

When I first announced my belief that such objects in natural history might be found, I little thought to have seen it realised, to such a degree as has now happened in the little circle of my knowledge. In the summer 1791,

Professor Playfair was to pass through Cumberland. I begged that he would inquire of Mr Wright, at the Low-wood Inn, for those objects which he was to endeavour to procure for me, and to examine the limestone quarry in which I had found the specimen with entrochi. He went through another part of those primary mountains, and has found examples of this kind in the schisti; concerning which he has written me the following account.

"In a visit which I made to the Lakes of Cumberland in September 1791, in company with the Hon. Francis Charteris, I met with a limestone full of marine objects, though from its position it is certainly to be reckoned among the primary strata. The place where we found this stone was in the district of Lancashire, that is west of Windermere Lake, on the road from Ambleside to the north end of Coniston Lake, and not far from the point when you come in sight of the latter. Just about this spot we happened to meet with one of those people who serve as guides to travellers in those parts, and who told us, among other things, that stones with shells in them were often found not far from where we were then walking. We immediately began to look about for specimens of that kind, and soon met with several; the most remarkable of which was in a rock that rose a little above the surface, about 300 or 400 yards to the right of the road. It was a part of a limestone stratum, nearly vertical, and was full of bivalves with the impressions as strong as in a common secondary limestone. The strata on both sides had the same inclination, and were decidedly primary, consisting of the ordinary micaceous schistus. This however I need not remark to you, who know so well from your own observations that the whole of the country I am now speaking of has every character of a primary one. I, only mention it, that it may not be supposed that the rock in question was some fragment of a secondary stratum that remained, after the rest was washed away, superincumbent on the primary.

"After I had seen this rock, I recollected that you had told me of something of the same kind that you saw in a quarry at Low-wood Inn; and it may be that both belonged to the same stratum or body of strata; for the direction of the strata, as nearly as I could observe, was from S.W. to N.E.; and this also is nearly the bearing of Low-wood from the place where we now were. I send you a specimen, which you can compare with those you brought from the lime quarry at Low-wood."

I have examined this specimen, and find it to be the common schistus of that country, only containing many bivalve shells and fragments of entrochi and madrapore bodies, and mixed with pyrites.

I have already observed that one single example of a shell, or of its print, in a schistus, or in a stone stratified among those vertical or erected masses, suffices to prove the origin of those bodies to have been, what I had maintained them to be, water formed strata erected from the bottom of the sea, like every other consolidated stratum of the earth. But now, I think, I may affirm, that there is not, or rarely, any considerable extent of country of that primary kind, in which some mark of this origin will not be found, upon careful examination; and now I will give my reason for this assertion. I have been examining the south alpine country of Scotland, occasionally, for more than forty years back, and I never could find any mark of an organised body in the schistus of those mountains. It is true that I know of only one place where limestone is found among the strata; this is upon Tweed-side near the Crook. This quarry I had carefully examined long ago, but could find no mark of any organised body in it. I suppose they now are working some other of the vertical strata near those which I had examined; for, in the summer 1792, I received a letter from Sir James Hall, which I shall now transcribe. It is dated at Moffat, June 2. 1792.

"As I was riding yesterday between Noble-house and Crook, on the road to this place, I fell in with a quarry of alpine limestone; it consists of four or five strata, about three feet thick, one of them single, and the rest contiguous; they all stand between the strata of slate and schist that are at the place nearly vertical. In the neighbourhood, a slate quarry is worked of a pure blue slate; several of the strata of slate near the limestone are filled with fragments of limestone scattered about like the fragments of schist in the sandstone in the neighbourhood of the junction on our coast.[²²]

Footnote 22:[ (return) ] This has a reference to very curious observations which we made upon the east coast where these mountains terminate, and which I am to describe in the course of this work.

"Among the masses of limestone lately broken off for use, and having the fractures fresh, I found the forms of cockles quite distinct; and in great abundance.—I send you three pieces of this kind," etc.

It may perhaps be alleged that those mountains of Cumberland and Tweedale are not the primary mountains, but composed of the secondary schistus, which is every where known to contain those objects belonging to a former earth. Naturalists who have not the opportunity of convincing themselves by their proper examination, must judge with regard to that geological fact by the description of others. Now it is most fortunate for natural history, that it has been in this range of mountains that we have discovered those marks of a marine origin; for, I shall afterwards have occasion to give the clearest light into this subject, from observations made in other parts of those same mountains of schist, by which it will be proved that they are the primary strata; and thus no manner of doubt will then remain in the minds of naturalists, who might otherwise suspect that we were deceiving ourselves, by mistaking the secondary for the primitive schistus.

I have only farther to observe, that those schisti mountains of Wales, of Cumberland, and of the south alpine part of Scotland, where these marine objects have been found, consist, of that species of stone which in some places makes the most admirable slate for covering houses; and, in other parts, it breaks into blocks that so much resemble wood in appearance, that, without narrow inspection, it might pass for petrified wood.

We are therefore to conclude that the marks of organised bodies in those primary mountains are certainly found; at the same time the general observation of naturalists has some foundation, so far as the marks of organised bodies are both rarely to be met with in those masses, and not easily distinguished as such when they are found.

But this scarcity of marine objects is not confined to those primary mountains, as they are called; for among the most horizontal strata, or those of the latest production, there are many in which, it is commonly thought, no marine calcareous objects are to be found; and this is a subject that deserves to be more particularly considered, as the theory may thus receive some illustration.

Sandstone, coal, and their accompanying strata, are thought to be destitute of calcareous marine productions, although many vestiges of plants or vegetable productions are there perceived. But this general opinion is neither accurate nor true; for though it be true that in the coal and sandstone strata it is most common to find marks of vegetable production, and rarely those calcareous bodies which are so frequent in the limestone, yet it is not unusual for coal to be accompanied with limestone formed of shells and corals, and also with ironstone containing many of those marine objects as well as wood. Besides, sandstone frequently contains objects which have been organised bodies, but which do not belong to the vegetable kingdom, at least to no plant which grows upon the land, but would seem to have been some species of zoophite perhaps unknown.

I have also frequently seen the vestige of shells in sandstone, although in these strata the calcareous bodies are in general not perceived. The reason of this is evident. When there is a small proportion of the calcareous matter in the mass of sand which is pervious to steam and to the percolation of water, the calcareous bodies may be easily dissolved, and either carried away or dispersed in the mass; or even without being thus dispersed by means of solution, the calcareous matter may be absorbed by the siliceous substance of the stratum by means of fusion, or by heat and cementation. The fact is, that I have seen in sandstone the empty mould of marine shells with some siliceous crystallization, so far as I remember, which corresponded perfectly with that idea. The place I saw this was in a fine white sandstone accompanying the coal, upon the sea side at Brora in Sutherland.

Mineralogy is much indebted to Mr Pallas for the valuable observations which he has given of countries so distant from the habitations of learned men. The physiology of the globe has also been enriched with some interesting observations from the labours of this learned traveller. But besides giving us facts, Mr Pallas has also reasoned upon the subject, and thus entered deep into the science of Cosmogeny; here it is that I am afraid he has introduced some confusion into the natural history of the earth, in not properly distinguishing the mineral operations of the globe, and those again which belong entirely to the surface of the earth; perhaps also in confounding the natural effects of water upon the surface of the earth, with those convulsions of the sea which may be properly considered as the accidental operations of the globe. This subject being strictly connected with the opinions of that philosopher with regard to primitive mountains, I am obliged to examine in this place matters which otherwise might have come more properly to be considered in another.

M. Pallas in his Observations sur la formation des montagnes, (page 48) makes the following observations.

"J'ai déjà dit que la bande de montagnes primitives schisteuses hétérogènes, qui, par toute la terre, accompagne les chaines granitiques, et comprend les roches quartzeuses et talceuses mixtes, trapézoïdes, serpentines, le schiste corne, les roches spathiques et cornées, les grais purs, le porphyre et le jaspre, tous rocs fêlés en couches, ou presque perpendiculaires, ou du moins très-rapidement inclinées, (les plus favorables à la filtration des eaux), semble aussi-bien que le granit, antérieure à la création organisée. Une raison très-forte pour appuyer cette supposition, c'est que la plupart de ces roches, quoique lamelleuse en façon d'ardoise, n'a jamais produit aux curieux la moindre trace de pétrifactions ou empreintes de corps organisés. S'il s'en est trouvé, c'est apparemment dans des fentes de ces roches où ces corps ont été apportés par un deluge, et encastrées apres dans une matière infiltrée, de même qu'on a trouvé des restes d'Eléphans dans le filon de la mine d'argent du Schlangenberg.[²³] Les caractères par lesquels plusieurs de ces roches semblent avoir souffert des effets d'un feu-très-violent, les puissantes veines et amas des minéraux les plus riches qui se trouvent principalement dans la bande qui en est composée, leur position immédiate sur le granit, et même le passage, par lequel on voit souvent en grand, changer le granit en une des autres espèces; tout cela indique une origine bien plus ancienne, et des causes bien différentes de celles qui ont produit les montagnes secondaires."

Footnote 23:[ (return) ] This is a very natural way of reasoning when a philosopher finds a fact, related by some naturalists, that does not correspond with his theory or systematic view of things. Here our author follows the general opinion in concluding that no organised body should be found in their primitive strata; when, therefore, such an object is said to have been observed, it is supposed that there may have been some mistake with regard to the case, and that all the circumstances may not have been considered. This caution with regard to the inaccurate representation of facts, in natural history, is certainly extremely necessary; the relicts of an elephant found in a mineral vein, is certainly a fact of that kind, which should not be given as an example in geology without the most accurate scientifical examination of the subject.

Here M. Pallas gives his reason for supposing those mountains primitive or anterior to the operations of this globe as a living world; first, because they have not, in general, marks of animals or plants; and that it is doubtful if they ever properly contain those marks of organised bodies; secondly, because many of those rocks have the appearance of having suffered the effects of the most violent fire. Now, What are those effects? Is it in their having been brought into a fluid state of fusion. In that case, no doubt, they may have been much changed from the original state of their formation; but this is a very good reason why, in this changed state, the marks of organised bodies, which may have been in their original constitution, should be now effaced.

The third reason for supposing those mountains primitive, is taken from the metallic veins, which are found so plentifully in these masses. Now, had these masses been the only bodies in this earth in which those mineral veins were found, there might be some species of reason for drawing the conclusion, which is here formed by our philosopher. But nothing is so common (at least in England) as mineral veins in the strata of the latest formation, and in those which are principally formed of marine productions; consequently so far from serving the purpose for which this argument was employed, the mineral veins in the primitive mountains tend to destroy their originality, by assimilating them in some respect with every other mass of strata or mountain upon the globe.

Lastly, M. Pallas here employs an argument taken from an appearance for which we are particularly indebted to him, and by which the arguments which have been already employed in denying the originality of granite is abundantly confirmed. It has been already alleged, that granite, porphyry, and whinstone, or trap, graduate into each other; but here M. Pallas informs us that he has found the granite not only changed into porphyry, but also into the other alpine compositions. How an argument for the originality of these mountains can be established upon those facts, I am not a little at a loss to conceive.

The general mineralogical view of the Russian dominions, which we have, in this treatise, may now be considered with regard to that distinction made by naturalists, of primitive, secondary, and tertiary mountains, in order to see how far the observations of this well informed naturalist shall be found to confirm the theory of the earth which has been already given, or not.

The Oural mountains form a very long chain, which makes the natural division betwixt Europe and Asia, to the north of the Caspian. If in this ridge, as a centre of elevation, and of mineral operations, we shall find the greatest manifestation of the violent exertion of subterraneous fire, or of consolidating and elevating operations; and if we shall perceive a regular appearance of diminution in the violence or magnitude of those operations, as the places gradually recede from this centre of active force; we may find some explanation of those appearances, without having recourse to conjectures which carry no scientific meaning, and which are more calculated to confound our acquired knowledge, than to form any valuable distinction of things. Let us consult M. Pallas how far this is the case, or not.

After having told us that all those various alpine schisti, jaspers, porphyries, serpentines, etc. in those mountains, are found mutually convertible with granite, or graduating into each other, our author thus continues, (p. 50).

"On entrevoit de certaines loix à l'égard de l'arrangement respectif de cet ordre secondaire d'anciennes roches, par tous les systèmes de montagnes qui appartiennent à l'Empire Russe. La chaîne Ouralique, par exemple, a du côté de l'Orient sur tout sa longueur, une très-grande abondance de schistes cornés, serpentins et talceux, riches en filons de cuivre, qui forment le principal accompagnement du granite, et en jaspres de diverses couleurs plus extérieurs et souvent comme entrelacés avec les premiers, mais formant des suites de montagnes entières, et occupant de très-grands espaces. De ce même côté, il y paraît beaucoup de quartz en grandes roches toutes pures, tant dans la principale chaîne que dans le noyau des montagnes de jaspre, et jusques dans la plaine. Les marbres spateux et veinés, percent en beaucoup d'endroits. La plupart de ces espèces ne paraissent point du tout à la lisière occidentale de la chaîne, qui n'est presque que de roche mélangée de schistes argileux, alumineux, phlogistique, etc. Les filons des mines d'or mêlées, les riches mines de cuivre en veines et chambrées, les mines de fer et d'aimant par amas et montagnes entières, sont l'apanage de la bande schisteuse orientale; tandis que l'occidentale n'a pour elle que des mines de fer de dépôts, et se montre généralement très-pauvre en métaux. Le granit de la chaîne qui borde la Sibérie, est recouvert du côté que nous connaissons de roches cornées de la nature des pierres à fusil, quelquefois tendant à la nature d'un grais fin et de schistes très-métallières de différente composition. Le jaspre n'y est qu'en filons, ou plans obliques, ce qui est très-rare pour la chaîne Ouralique, et s'observe dans la plus grande partie de la Sibérie, à l'exception de cette partie de sa chaîne qui passe près de la mer d'Okhotsk, ou le jaspre forme derechef des suites de montagnes, ainsi que nous venons de le dire des monts Ourals; mais comme cette roche tient ici le côté méridionale de la chaîne Sibérienne, et que nous ne lui connaissons point ce côté sur le reste de sa longueur, il se pourrait que le jaspre y fût aussi abondant. Il faudrait, au reste, bien plus de fouilles et d observations pour établir quelque chose de certain sur l'ordre respectif qu'observent ces roches."

I would now ask, if in all this account of the gradation of rock from the Oural mountains to the sandy coast of the Baltic, there is to be observed any clear and distinctive mark of primitive, secondary, and tertiary, mountains, farther than as one stratum may be considered as either prior or posterior to another stratum, according to the order of superposition in which they are found. We have every where evident marks of the formation of strata by materials deposited originally in water; for the most part, there is sufficient proof that this water in which those materials had been deposited was the sea; we are likewise assured that the operations of this living world producing animals, must have, for a course of time, altogether inconceivably been exerted, in preparing materials for this mass; and, lastly, from the changed constitution of those masses, we may infer certain mineral operations that melt the substance and alter the position of those horizontal bodies. Such is the information which we may collect from this mineral description of the Russian Dominions.

If we compare some of the Oural mountains with the general strata of the Russian plains, then, as to the contained minerals, we may find a certain diversity in those two places; at the same time, no greater perhaps than may be found betwixt two different bodies in those same plains, for example, chalk and flint. But when we consider those bodies of the earth, or solid strata of the globe, in relation to their proper structure and formation, we surely can find in this description nothing on which may be founded any solid opinion with regard to a different original, however important conclusions may perhaps be formed with regard to the operations of the globe, from the peculiar appearances found in alpine.

From this detail of what is found in the Oural mountains, and in the gradation of country from those mountains to the plains of Russia, we have several facts that are worthy of observation. First extensive mountains of jasper. I have a specimen of this stone; it is striped red and green like some of our marly strata. It has evidently been formed of such argillaceous and siliceous materials, not only indurated, so as to lose its character, as an argillaceous stone, but to have been brought into that degree of fusion which produces perfect solidity. Of the same kind are those hornstein rocks of the nature of flint, sometimes tending to the nature of a fine sandstone. Here is the same induration of sandstone by means of fusion, that in the argillaceous strata has produced jasper. But oblique veins of jasper are represented as traversing these last strata; now this is a fact which is not conceivable in any other way, than by the injection or transfusion of the fluid jasper among those masses of indurated strata.

All this belongs to the east side of the mountains. On the west, again, we find the same species of strata; only these are not changed to such a degree as to lose their original character or construction, and thus to be termed differently in mineralogy.

Our author then proceeds. (p. 53.)

"Nous pourrons parler plus décisivement sur les montagnes secondaires et tertiaires de l'Empire, et c'est de celles-là, de la nature, de l'arrangement et du contenu de leurs couches, des grandes inégalités et de la forme du continent d'Europe et d'Asie, que l'on peut tirer avec plus de confiance quelques lumières sur les changemens arrivés aux terres habitables. Ces deux ordres de montagnes présentent la chronique de notre globe la plus ancienne, la moins sujette aux falsifications, et en même-tems plus lisible que le caractère des chaînes primitives; ce font les archives de la nature, antérieures aux lettres et aux traditions les plus reculées, qu'il étoit réservé à notre siècle observateur de feuiller, de commenter, et de mettre au jour, mais que plusieurs siècles après le nôtre n'épuiseront pas.

"Dans toute l'étendue de vastes dominations Russes, aussi bien que dans l'Europe entière, les observateurs attentifs ont remarqué que généralement la band schisteuse des grandes chaînes se trouve immédiatement recouverte ou cottée par la bande calcaire. Celle-ci forme deux ordres de montagnes, très-différentes par la hauteur, la situation de leurs couches, et la composition de la pierre calcaire qui les compose; différence qui est très-évidente dans cette bande calcaire qui forme la lisière occidentale de toute la chaîne Ouralique, et dont le plan s'étend par tout le plat pays de la Russie. L'on observerait la même chose à l'orient de la chaîne, et dans toute l'étendue de la Sibérie, si les couches calcaires horizontales n'y étaient recouvertes par les dépôts postérieures, de façon qu'il ne paraît à la surface que les parties les plus faillantes de la bande, et si ce pays n'étoit trop nouvellement cultivé et trop peu exploité par des fouilles et autres opérations, que des hommes industrieux ont pratiqué dans les pays anciennement habités. Ce que je vais exposer sur les deux ordres de montagnes calcaires, se rapportera donc principalement à celles qui sont à l'occident de la chaîne Ouralique.

"Ce côté de la dite chaîne consiste sur cinquante à cent verstes de largeur, de roche calcaire solide, d'un grain uni, qui tantôt ne contient aucune trace de productions marines, tantôt n'en conserve que des empreintes aussi légères qu'éparses. Cette roche s'élève en montagnes d'une hauteur très-considérable, irrégulières, rapides, et coupées de vallons escarpés. Ses couches, généralement épaisses, ne sont point de niveau, mais très-inclinées à l'horizon, paralleles, pour la plupart, à la direction de la chaîne, qui est aussi ordinairement celle de la bande schisteuse;—au lieu que du côté de l'orient les couches calcaires sont au sens de la chaîne en direction plus ou moins approchante de l'angle droite. L'on trouve dans ces hautes montagnes calcaires de fréquentes grottes et cavernes très-remarquables, tant par leur grandeur que par les belles congélations et crystallizations stalactiques dont elles s'ornent. Quelques-unes de ces grottes ne peuvent être attribuées qu'à quelque bouleversement des couches; d'autres semblent devoir leur origine à l'écoulement des sources souterraines qui ont amolli, rongé et charrié une partie de la roche qui en étoit susceptible.

"En s'éloignant de la chaîne, on voit les couches calcaires s'aplanir assez rapidement, prendre une position horizontale, et devenir abondantes en toute forte de coquillages, de madrépores, et d'autres dépouilles marines. Telles on les voit par-tout dans les vallées les plus basses qui se trouvent aux pieds des montagnes (comme aux environs de la rivière d'Oufal; telles aussi, elles occupent tout l'étendue de la grande Russie, tant en collines qu'en plat pays; solides tantôt et comme semées de productions marines; tantôt toutes composées de coquilles et madrépores brisées, et de ce gravier calcaire qui se trouve toujours sur les parages ou la mer abonde en pareilles productions; tantôt, enfin, dissoutes en craie et en marines, et souvent entremêlées de couches de gravier et de cailloux roulés."

How valuable for science to have naturalists who can distinguish properly what they see, and describe intelligibly that which they distinguish. In this description of the strata, from the chain of mountains here considered as primitive, to the plains of Russia, which are supposed to be of a tertiary formation, our naturalist presents us with another species of strata, which he has distinguished, on the one hand, in relation to the mountains at present in question, and on the other, with regard to the strata in the plains, concerning which there is at present no question at all. Now, let us see how these three things are so connected in their nature, as to form properly the contiguous links of the same chain.

The primary and tertiary masses are bodies perfectly disconnected; and, without a medium by which they might be approached, they would be considered as things differing in all respects, consequently as having their origins of as opposite a nature as are their appearances. But the nature and formation of those bodies are not left in this obscurity; for, the secondary masses, which are interposed, participate so precisely of what is truly opposite and characteristic in the primary and tertiary masses, that it requires nothing more than to see this distinction of things in its true light, to be persuaded, that in those three different things we may perceive a certain gradation, which here takes place among the works of nature, and forms three steps distinguishable by a naturalist, although in reality nothing but the variable measure of similar operations.

We are now to assimilate the primary and tertiary masses, which are so extremely different, by means of the secondary masses, which is the mean. The primary and tertiary differ in the following respects: The one of these contains the relicts of organised bodies which are not observed in the other. But in the species containing these distinguishable bodies, the natural structure and position of the mass is little affected, or not so much as to be called into doubt. This, however, is not the case with the other; the species in which organised bodies do not appear, is in general so indurated or consolidated in its structure, and changed in its position, that this common origin of those masses is by good naturalists, who have also carefully examined them, actually denied. Now, the secondary masses may be considered, not only as intermediate with respect to its actual place, as M. Pallas has represented it, but as uniting together the primary and tertiary, or as participating of the distinguishing characters of the other two. It is homologated with the primitive mountains, in the solidity of its substance and in the position of its strata; with the tertiary species, again, in its containing marks of organised bodies. How far this view of things is consistent with the theory of the earth now given, is submitted to the consideration of the unprejudiced.

Let us see what our learned author has said farther on this subject, (page 65).

"Je dois parler d'un ordre de montagnes très-certainement postérieur aux couches marines, puisque celles-ci, généralement lui servent de base. On n'a point jusqu'ici observé une suite de ces montagnes tertiaires, effet des catastrophes les plus modernes de notre globe, si marquée et si puissante, que celle qui accompagne la chaine Ouralique ou côté occidentale fur tout la longueur. Cette suite de montagnes, pour la plupart composées de grais, de marnes rougeâtres, entremêlées de couches diversement mixtes, forme une chaîne par-tout séparée par une vallée plus ou moins large de la bande de roche calcaire, dont nous avons parlé. Sillonnée et entrecoupée de fréquens vallons, elles s'élève souvent à plus de cent toises perpendiculaires, se répand vers les plaines de la Russie en traînées de collines, qui séparent les rivières, en accompagnant généralement la rive boréale ou occidentale, et dégénère enfin en déserts sableux qui occupent de grands espaces, et s'étendent surtout par longues bandes parallèles aux principales traces qui suivent les cours des rivieres. La principale force de ces montagnes tertiaires est plus près de la chaîne primitive par-tout le gouvernement d'Orenbourg et la Permie, ou elle consiste principalement en grais, et contient un fond inépuisable de mines de cuivre sableuses, argileuses, et autres qui se voient ordinairement dans les couches horizontales. Plus loin, vers la plaine, sont des suites de collines toutes marneuses, qui abondent autant en pierres gypseuses, que les autres en minerais cuivreux. Je n'entre pas dans le détail de celles-ci, qui indiquent sur-tout les sources salines; mais je dois dire des premières, qui abondent le plus et dont les plus hautes élévations des plaines, même celle de Moscou, sont formées, qu'elles contiennent très-peu de traces de productions marines, et jamais des amas entiers de ces corps, tels qu'une mer reposée pendant des siècles de suite a pu les accumuler dans les bancs calcaires. Rien, au contraire, de plus abondant dans ces montagnes de grais stratifié sur l'ancien plan calcaire, que des troncs d'arbres entières et des fragmens de bois pétrifié, souvent minéralisé par le cuivre ou le fer; des impressions de troncs de palmires, de tiges de plantes, de roseau, et de quelques fruits étrangers; enfin des ossemens d'animaux terrestres, si rares dans les couches calcaires. Les bois pétrifiés se trouvent jusques dans les collines de sable de la plaine; l'on en tire, entr'autres, des hauteurs sablonneuses aux environs de Sysran sur la Volga, changés en queux très-fin, qui a conservé jusqu'à la texture organique du bois, et remarquables sur-tout par les traces très-évidentes de ces vers rongeurs qui attaquent les vaisseaux, les pilotis et autres bois trempés dans la mer, et qui sont proprement originaires de la mer des Indes."

This philosopher has now given us a view of what, according to the present fashion of mineral philosophy, he has termed montagnes primitives, secondaires, et tertiaires. The first consists in masses and strata, much indurated and consolidated, and greatly displaced in their position; but the character of which is chiefly taken from this, that they contain not any visible mark of animal or vegetable bodies.

The second are formed in a great measure of marine productions, are often no less consolidated than those of the first class, and frequently no less changed in their natural shape and situation.

The third again have for character, according to this learned theorist, the containing of those organised bodies which are proper to the earth, instead of those which in the second class had belonged to the sea; in other respects, surely there is no essential difference. It is not pretended that these tertiary strata had any other origin, than that of having been deposited in water; it is not so much as suspected, that this water had been any other than that of the sea; the few marine bodies which M. Pallas here acknowledges, goes at least to prove this fact: and with regard to the mineral operations which had been employed in consolidating those water formed strata, it is impossible not to be convinced that every effect visible in the other two are here also to be perceived.

From this view of mineral bodies, taken from the extensive observations of the Russian dominions, and from the suppositions of geologists in relation to those appearances, we should be led to conclude that the globe of this earth had been originally nothing but an ocean, a world containing neither plant nor animal to live, to grow and propagate its species. In following a system founded on those appearances, we must next suppose, that to the sterile unorganised world there had succeeded an ocean stored with fish of every species. Here it would be proper to inquire what sustained those aquatic animals; for, in such a system as this, there is no provision made for continuing the life even of the individuals, far less of feeding the species while, in an almost infinite succession of individuals, they should form a continent of land almost composed of their exuviae.

If fish can be fed upon water and stone; if siliceous bodies can, by the digesting powers of animals, be converted into argillaceous and calcareous earths; and if inflammable matter can be prepared without the intervention of vegetable bodies, we might erect a system in which this should be the natural order of things. But to form a system in direct opposition to every order of nature that we know, merely because we may suppose another order of things different from the laws of nature which we observe, would be as inconsistent with the rules of reasoning in science, by which the speculations of philosophy are directed, as it would be contrary to common sense, by which the affairs of mankind are conducted.

Still, however, to pursue our visionary system, after a continent had been formed from the relicts of those animals, living, growing, and propagating, during an indefinite series of ages, plants at last are formed; and, what is no less wonderful, those animals which had formed the earth then disappear; but, in compensation, we are to suppose, I presume, that terrestrial animals began. Let us now reason from those facts, without either constraining nature, which we know, or forming visionary systems, with regard to things which are unknown. It would appear, that at one period of time, or in one place, the matter of the globe may be deposited, in strata, without containing any organised bodies; at another time, or in another place, much animal matter may be deposited in strata, without any vegetable substance there appearing; but at another period, or at another time, strata may be formed with much vegetable matter, while there is hardly to be observed any animal body. What then are we to conclude upon the whole? That nature, forming strata, is subject to vicissitudes; and that it is not always the same regular operation with respect to the materials, although always forming strata upon the same principles. Consequently, upon the same spot in the sea, different materials may be accumulated at different periods of time, and, conversely, the same or similar materials may be collected in different places at the same time. Nothing more follows strictly from the facts on which we now are reasoning; and this is a conclusion which will be verified by every appearance, so far as I know.

Of this I am certain, that in a very little space of this country, in many places, such a course of things is to be perceived. Nothing so common as to find alternated, over and over again, beds of sand-stone without animal bodies, beds of coal and schistus abounding with vegetable bodies, beds of lime-stone formed of shells and corals, and beds or particular strata of iron-stone containing sometimes vegetable sometimes animal bodies, or both. Here, indeed, the strata are most commonly inclined; it is seldom they are horizontal; consequently, as across the whole country, all the strata come up to the day, and may be seen in the beds of our rivers, we have an opportunity of observing that great variety which is in nature, and which we are not able to explain. This only is certain, from what we see, that there is nothing formed in one epoch of nature, but what has been repeated in another, however dissimilar may be the operations which had intervened between those several epochs.

It must not be alleged, that the heights of the Oural mountains, or the hardness of their rocks, make an essential distinction between them and the argillaceous or arenaceous strata of the plains; solidity and hardness, as well as changes in their height and natural position, has been superinduced in operations posterior to the collection of those masses,—operations which may be formed in various degrees, even in the different parts of the same mass. If this is the case, there can be no difficulty in conceiving a stratum, which appears to be argillaceous or marly in the plains, to be found jasper in the Oural mountains. But there is nothing in the Oural mountains, that may not be found some where or other in the plains, although the soft and easily decomposing argillaceous strata be not found upon the Oural mountains, or the Alps, for this reason, that had those mountains been formed of such materials, there had not been a mountain there at this day.

But surely the greatest possible error, with regard to the philosophy of this earth, would be to confound the sediment of a river with the strata of the globe; bodies deposited upon the surface of the earth, with those sunk at the bottom of the sea; and things which only form the travelled or transported soil, with those which constitute the substratum or the solid earth. How far M. Pallas has committed this oversight, I leave others to determine. After mentioning those strata in which wood is found petrified, and metallic minerals formed, he thus proceeds, (page 69).

"Dans ces mêmes dépôts sableux et souvent limoneux, gisent les restes des grands animaux de l'Inde: ces ossemens d'éléphans, de rhinocéros, de buffles monstrueux, dont on déterre tous les jours un si grand nombre, et qui font l'admiration des curieux. En Sibérie, où l'on à découvert le long de presque toutes les rivières ces restes d'animaux étrangers, et l'ivoire même bien conservé en si grande abondance, qu'il forme un article de commerce, en Sibérie, dis je, c'est aussi la couche la plus moderne de limon sablonneux qui leur sert de sépulture, et nulle part ces monumens étrangers sont si frequens, qu'aux endroits où la grande chaine, qui domine surtout la frontière méridionale de la Sibérie, offre quelque dépression, quelque ouverture considérable.

"Ces grands ossemens, tantôt épars tantôt entassés par squelettes, et même par hécatombes, considérée dans leurs sites naturels, m'ont sur-tout convaincu de la réalité d'un déluge arrivé sur notre terre, d'une catastrophe, dont j'avoue n'avoir pu concevoir la vraisemblance avant d'avoir parcouru ces places, et vu, par moi-même, tout ce qui peut y servir de preuve à cet évènement mémorable[²⁴]. Une infinité de ces ossemens couchés dans des lits mêlés de petites tellines calcinées, d'os de poissons, de glossopètres, de bois chargés d'ocre, etc. prouve déjà qu'ils ont été transportés par des inondations. Mais la carcasse d'un rhinocéros, trouvé avec sa peau entière, des restes de tendons, de ligamens, et de cartilages, dans les terres glacées des bords du Viloûi, dont j'ai déposé les parties les mieux conservées au cabinet de l'Académie, forme encore une preuve convaincante que ce devait être un mouvement d'inondation des plus violens et des plus rapides, qui entraîna jadis ces cadavres vers nos climats glacés, avant que la corruption eût le tems, d'en détruire les parties molles. Il seroit à souhaiter qu'un observateur parvint aux montagnes qui occupent l'espace entre les fleuves Indighirka et Koylma où selon le rapport des chasseurs, de semblables carcasses d'éléphans et d'autres animaux gigantesques encore revêtues de leurs peaux, ont été remarquées à plusieurs reprises."

Footnote 24:[ (return) ] Voyez le Mémoire, imprimé dans le XVII. volume des nouveaux Commentaires de l'Académie Imperiale de Petersbourgh.

The question here turns upon this, Are the sea shells and glossopetrae, which are thus found deposited along with those skeletons, in their natural state, or are they petrified and mineralised. If the productions of the sea shall here be found collected along with bodies belonging to the surface of the earth, and which had never been within the limits of the sea, this would surely announce to us some strange catastrophe, of which it would be difficult, perhaps, to form a notion; if, on the contrary, those marine productions belong to the solid strata of the earth, in the resolution or decay of which they had been set at liberty, and were transported in the floods, our author would have no reason from those appearances to conclude, there had existed any other deluge than those produced by the waters of the land[²⁵].

Footnote 25:[ (return) ] Since writing this, I find my doubts in a great measure resolved, in reading M. Pallas's Journal, translated from the German by M. Gauthier de la Peyronie. What I had suspected is, I think, confirmed in the distinct account which M. Pallas has given of those occasions in which the bones of land animals and marine objects are found buried together. The marine objects are mineralised; consequently, they have proceeded from the decomposition of the solid strata; and, having been travelled in the running water of the surface of the earth, they must have been deposited in those beds of rivers, which now are dry, alongst with the bones, or the entire bodies of terrestrial animals, the remains of which are now found there. This argument, from the state of those marine bodies will not be allowed, perhaps by the generality of mineralists, who attribute to the operations of water every species of petrifaction or mineralisation; but, until some species of proof be given with regard to the truth of that theory, which vulgar error first suggested, I must reason from a theory, in proof of which I have given clear examples, and, I think, irrefragable arguments, which shall be more and more illustrated. Thus may be removed the necessity of a general deluge, or any great catastrophe, in order to bring together things so foreign to each other; but at the same time we would ascertain this fact, That formerly the Elephant and Rhinoceros had lived in Siberia. (See Voyage de Pallas, Tom. II. p. 377 and 403.)

Having thus endeavoured to remove this prevailing prejudice, of there being primitive parts in this earth, parts of which the composition and constitution are not to be explained upon the principles of natural philosophy, it will be proper to inquire, how far there may be in the theory, which has now been given, principles by which may be explained those appearances that have led natural philosophers to form conclusions, of there being in this earth parts whose origin may not be traced; and of there being parts whose origin may not be explained upon the same principles which apply so well to all the rest.