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depofition and hardening of a fand; air to convey them as there is in mot

and ftill, as it is cut away for ufe, fresh fupplies fill up the place.

Dr Hutton is fingular, fo far as I know, in fuppofing fufion neceffary to the hardening of ftrata; he is the very firft, perhaps, who ever imagined that calcareous fpar was the effect of it. Men had been fomewhat attentive to mineral crystallizations, but reafon ing from analogy, they never confidered them as productions from matter in a fused fluid state, and for the beft of reafons. No man had ever known the parts of a compound ftone, fuppofe flint and fpar, when melted into glafs, afterwards feparate, and each earth fhoot into cryftals by itfelf: quite the contrary; the effects of fire on foffils are almost universally to blend different earths and ftones together into a folid homogeneous glafs. But chemifts had, in a thousand inftances, feen juft fuch a feparation take place when different falts were diffolved in water, each being commonly detached, and crystallizing by itfelf. They were led to conclude, that fpars and cryftals had been formed in a fimilar manner. They allowed that these fubftances were scarce foluble in water, but they had centuries to form in; and, as in most other crystallizations, it was found that the hardness was generally proportioned to the flownefs of formation, this might account for even the extreme firmnefs of the gem. Allowing that all this is infufficient, many things are to be fuppofed 'ere we think of fire. Is it not probable that many minerals grow? does not analogy lead us to believe it? is cryftallization to be accounted for on ary mechanical principles? If any one will infift, which he has not always a right to do, that they increase only by juxtapofition, will he refufe them the power of affimilation? or if he deny them that, it is undeniable that there is a power of attraction which may, in time, draw fimilar principles together, even where there is as little water or

ftrata. We fee in animals and vege tables, in falts and inflammable fubfrances, how, out of a few principles differently combined, fuch varied bodies are produced; how there is a continual decompofition and recompo fition: fhall we venture to fay that no fuch things take place, no fimilar pow ets act in the mineral kingdom? Our experiments may not have fucceeded, though, indeed, such have hardly been made hitherto; hall we, therefore, decide that the mighty chemist, who makes trees and men his alembics, has no other powers for producing or hardening minerals but fire, especially as we know that its effect is only to confound them? Might we not as well be told, that the hardness of our bones was owing to fufion?

It is dangerous to meddle with fire, especially when that dreadful agent is fo ftrong and univerfal as the prefent theory requires it; we need not, therefore, be furprised if it has injured the author's reafoning in more places than one, in fpite of the afliftance he has called in. Every one would object to the theory at once; How is it poffible for calcareous earth to be fused, wit! out parting with its fixed air? The answer is, that it was done under an immenfe preffure. Grant it; in fome places there are many beds of earth over the melted marble; through these the air might not penetrate; but in many places the calcareous ftrata, or at leaft pieces of fpar, &c. must have been immediately under the water; would any depth of this element prevent the extrication of air?

The fire has alfo occafioned another palpable mistake, in fpeaking of the Portfoy granite. We will not aver, that there never was an instance of quartz and feldtfpat, with fome mica, fufed together, where, on cooling, any one of thefe ingredients feparated, to confolidate into crystals by itself in the midst of the others; we will pafs this over: but that feldtfpat, a fub

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ftance fo easily fufible, fhould be the firit to chrystallize; and that the quartz, which requires a prodigious degree of heat to melt it, fhould remain fluid till it filled up the interftices of the other's chryftals fo compleatly, is altogether irreconcileable with every thing we know of the action of heat in circumftances whatever. This is not the only place where the fame objection may be urged.

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In furveying the fine fpecimens of drufen, or hollow ftones, with diftinét alternate layers of spar, rock-crystal &c. inftead of faying, all this must be the effect of fire, while fire was never known to produce any thing fimilar, how fuperior the candid exclamation of a celebrated Genevan philofopher, quelles mysteres! Let us push the neceffary confequences of the fuppofed fire: Is it at all reconcilcable with the minutely laminated appearance of many ftrata, especially of the fchiftic kind? Are there not, in almost every ftratum, bodies which, to have been fufed, would have required a heat capable of changing the whole ftratum into one mafs of glass?

Are there not many ftones, e. g. quartz, nay entire ftrata, which by fire are rendered brittle, and fall to pieces, inftead of hardening; fome of which would perhaps diffipate 'ere they could be fufed? In a word, to establish this theory, almost every known law of fufion must be trampled under foot by preffure.

Veins and fiffures in ftrata, the author fays, can only be the confequence of fufion; why not of fimple exficcation? In numberless inftances, do we not fee them produced merely by expo. fure to the air? As to thofe fiffures being always in proportion to the confolidation of the ftratum, which however we will venture to fay is by no means the cafe, it is equally accountable on the one fuppofition as on the other.

We next follow the theorist to the elevation of the ftrata. It is a beautiful srait in this fyltem, to make the fame

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caufe produce two grand effects; but truth must be confulted rather than what to us might appear moft fimple.

The immenfe preffure, which form. erly was to operate in preventing the evolution of any aeriform fluid when marble was to be fufed, is now overlooked when the Alps and Andes are to be reared, and the expanfive power of heat is allowed to be inconceivable. The Doctor certainly cannot mean that the mountains of our globe were raifed to their prefent height folely by the expansion of the folid matter which they contain; it must have been by the force of fteam, or of fome elastic fluid. Confequently cavities must have been left beneath, nearly equal to the bulk of the matter raifed. Are we to fuppose then, that the water of the ocean was carefully excluded from the cavi ties? if not, it must have rushed in, and, of confequence, the skeleton, or refiduum of the former continent, now worn down to nearly a level with the deep, inftead of being drowned by the rifing of the new one, would again, by the retreat of the water, emerge to a confiderable height. This difficulty has not been attended to; but no won der that, in the arduous task of raifing a world, fuch things fhould be difregarded.

The irregular pofition of ftrata, their breaks, flexures, &c. are given as an argument for this elevation by fire; and no doubt, in many cafes, we cannot otherwife account for them; but let it be considered, that these are not fo univerfal as has been fuppofed. Many of the largest mountains are formed of regular concentric ftrata; those of Jura, Sauffure compares to a pack of cards bent to a ridge. The higheft central mountains of the Alps are of ftrata parallel to the chain, and to each other. The ftrata mentioned by M. Voigt, in your last Number, are in the fame manner applied exactly to the contour of the original mountain. Every inftance, in a word, favours, and has led to the idea, that the strax 2

ta, on whose formation we can rea- heterogeneous parts in its fubflance than the other. Granting the fusion of the toadstone, does it not rather ar gue against the Doctor's theory? does it not feem to indicate that, in whatever circumftances fubterraneous fire operates, it is only with certain ma terials that it can form a lava, or these only it can bring into a state of fufion? the other fhiata, therefore, have never been fufed.

fon, have been originally formed, not at all by a mere horizontal depofition, but wherever a nucleas was found they incrusted it on all fides, as by a fort of cryftalization.

The hypothefis of mineral veins is totally gratuitous; and the idea of a central fire from which they proceed, without the fhadow of evidence, is fit only for a theologian of the 12th centu■y, at a lofs where to place his hell.

Volcanoes are next mentioned as a proof of the internal heat; but it is now the common belief of thofe who have examined volcanoes, that they extend to no great depth, and proba bly not to any confiderable diftance; all agree that they are merely local. That they have their ufes in the economy of the globe, is certain; but that they act as fpiracles to give a vent to the central fire till it be neceffary to raise new continents, is a mere fuppofition; there is this objection to it befides, that the intervention of fome powers is neceffary to plug up these vents, and confine the heat when the fuppofed fire is to act in forming a new world. A great flaw this in a theory whofe beauty is to account for every thing by natural laws.

The Derbyshire toadstone, the Scotch nuhin, &c. are perhaps at prefent the moft puzzling to the naturalift who wishes to determine their origin. Their perfect fimilarity to lavas in fubftance, and the manner of their fituation, on the one hand; the veins of fpar, &c. which they contain, and the abfence of pumice, cinders, &c. on the other, fufpend his judgment, and have left a number of philofophers undetermined. Most probably that found among fecondary ftrata, as in Derbyshire, and in the coal and lime countries of ScotJand, is the effect of fufion; but much the greater part, which conftitutes the bafe of entire countries, and is placed in nearly vertical ftrata, has never undergone the operation of fire, and it is indeed found generally with fewer

But allowing our whin to have been fufed, it is certainly wrong to conclude from thence, that it has undergone the fame action of fire in other places, where perhaps it is never feen in fuch circumstances as it is with us; and ftill more to reafon from our country on the formation of all Europe, and of all the world. Sauffure met with it in no fuch circumstances among the Alps. M. Voigt mentions no fuch thing in his Letters. I know no foreign writer who has obferved it abroad.

So much for the principal parts of this theory; let us now take a view of the great outline altogether. What hath it taught us? Had any one faid, that fire raised all our mountains, we would anfwer, It may be fo; earthquakes are the only things we know capable of doing it; yet, after all, we have no certainty men never faw a mountain formed, except thofe made by volca noes, which are of a nature totally different from others. Had the fame, or another perfon, told us, that all our ftrata had been in fufion, he would likely not have been credited. But, admitting both affertions, what have we learned? The very things which a theory of the earth ought to teach, are paffed over in filence. Why are the highest, oldest mountains moftly of gra nite? Why are they generally fucceed ed in a fort of regular order by those of other kinds? Why of the fame aerated calcareous earth have we marble in fome places, chalk in others? Why, in one place a gem, elfewhere of the fame materials, have we left only a claył

Why

Why particular alternations, or fuccefLons of ftrata in particular countries? Why the dip, fo uniform in many, fo varied in fome places? Why petrifactions and impreffions, animal and vegetable, peculiar to fome ftrata? Why certain fubftances only found in certain ftrata, tho' of a nature totally different from that which contains them, e. g. the flints in chalk? In fhort, every information which one would naturally expect from a theory of the earth, is loft more compleatly here, than in any of the former; every thing is swallowed up in fufion, or blown to pieces by expanfion. A theory should not only account for what has been known, but fhould at once point out conclufions that were unperceived before. The one under confideration does this indeed by the lump: an that we fee is the effect of fire; every thing that can hereafter be found, may, in the fame manner, be accounted for: but, being able to fay this, are we one whit wifer than we were? Had the whole been given out as a pretty thought, an apperçue, it might have paffed fo; but to receive it as a theory, or to fuppofe it founded on a physical demonftration, would be to ftop the mouth of inquiry.

Such long frides, as have been taken from one conclufion to another of this demonstration, are a likely enough way to eternity; we are prepared, therefore, for the grand corollary with which the Doctor concludes, viz. that in our earth, as a habitable world, there is no veftige of a beginning no profpect of an end. Upon this, as a detached point, we have but two ways of reafoning, from analogy, and from obfervation.

Analogy teacheth us, that as there is a conftant fucceflion in every thing, individuals of every kind muft perifh; the animal, the plant (if there is any distinction betwixt a plant and an animal) muft die, that room may be made for another. Can we extend this to the earth? not without extreme caution. Were we Ptolemæ

ans, then our world would appear fo grand an object in nature, that it might be fuppofed, like the bafe of all, to continue for ever. But, confidered as aftronomy now fhews it, an infinitely fmall part, so to speak, of the univerfe, we drop our notions of its importance, we find it relatively no more than the most trifling infect. Shall it remain for ever?

Obfervation too, fhort as the life and annals of man are, has furnished fome things that feem to limit its period. If it can be proved, that now it is in a state materially different from what it was formerly in, this must go a great way, and we have facts little fhort of fuch a proof. That most of our prefent land has been under was ter is evident, that fuch another continent exifted before, as our own, is doubtful. The immenfe mountains of calcareous ftone, placed near the pri mitive Alps of the globe, fuppofing this tone to be from the exuvia of fhellfish, feem to fhow that that race had once occupied a much larger propor tion in the economy of nature than it now does. Our petrifactions fhow that formerly there exifted many spe cies, perhaps genera, of animals, now to all appearance extinct. The bones of the elephant, crocodile, &c. found foflil in the North of Europe, and in America, where thefe animals have long ceafed to exift, feem clearly to indicate a total change of climate, temperature, and inhabitants, in a great part of the globe. All these are fymp toms of fomething analogous to the ftages of increase, perfection, and decay, common to every being with which we are acquainted. But future. aftronomical obfervations must determine the matter.

Every theory of the earth hitherto given, appears to me, Sir, more or less liable to two great objections. One is, from an excefs of generalization, accounting for too many things by one caufe. Buffon afcribed too much to water, or at leaft to fimple depofition,

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Dr Hutton has done the fame by fire. Having a strong propenfity to account for every thing, and being acquainted with but a few of nature's agents and ways, we are obliged to give to each more than is its due, and will rather do this than wait till obfervation or experiment have fet us right. It was thus the mechanical philofophers, juftly proud of the aftonishing difcoveries they had made in the inanimate world, began to carry their rules into living fyftems, as if they had been only hydraulic machines. Electricity was thus ftretched, foon after the difcovery of its amazing effects, and thought ade. quate to the folution of all difficulties. Another capital objection to thefe theories is, that every one has founded his own on what he himself has obferved, most commonly on that part of a country in which he himself has refided, and has afterwards moft illogically argued from a part to the whole. This was a great defect in Whitehurst's theory. It was thus M. Voigt formed his opinion. This will, in a word, be found at the bottom of all. Buf fon's, and the prefent one, may indeed, be applied to every place; but where and how founded, let every one judge. While this principle prevails, the Alps and the Cordilleras are the places where moft truth is likely to be met with; ceteris paribus, therefore, more may be expected from the Ge

nevan philofophers than from others juft now; yet neither De Luc nor Sauffure, from what they faw, have ever entertained a furmise that any of the Alpine ftrata had been in fufion.

At prefent, Sir, and for a long time hence, it would be better to point out our ignorance, than to frame hypothe fes; to collect facts would be ftill better. The field is wide; the end is a great one. In fome future period man may be dignified with the difcovery; at prefent, it is far remote. Let the path be fteadily purfued: one fure ftep is a great deal, Truth can never be affected by prejudice or fuperftition. When afcertained, it must be truth, how much foever it may differ from common religious tenets, or from philofophical fancies. The Antepodes mult be believed in spite of decrees and anathemas; and a vacuum, in spite of nature's abhorrence. What the profe cution of this fubject of the earth's formation may at last lead to, we can◄ not fay. Though one could not help fmiling at the man who would offer to him the Mofaic account as a compleat fyftem of cofmology, yet as to the attempts hitherto made at a better, we may fay,

Cedite fcriptores
Nefcio quid majus nafcitur genefei.
I am, Sir,
Yours, &c.

G-D

An Account of a Book lately published in France, called Memoires de M. Goldoni, &c. written by himself. 3 vols. 8vo.

T

HE name of Goldoni is cele brated over all Europe. He undertook with fuccefs, to reform the theatre of his native country, and no dramatic author of our age has fhewn fuch amazing fecundity of invention. In a fingle year (1750) he compofed fixteen pieces, that were all reprefented on the theatre of St Ange at Venice. This immenfe exertion for a long time affected his health; but he

had come under engagements to the Public, which he refolved to fulfill. The fum-total of his works amounts to one hundred and fifty comedies, in verfe as well as in profe. He has feen eighteen editions of his theatre. He has diftinguifhed himself by an excellent fentimental comedy, in the French language, called Le Bourru Bienfaifant. Few authors have travelled more, or written fo much as Goldoni; and he alone is

equal

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