Chapter II (3)

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 analyzed; 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]

[Note 20: 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.

[Note 21: 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 alledged 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 traveled 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 travelers 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]

[Note 22: 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.