ed, cafts fome glofs of speciousness over fome of his fuppofi tions. When excavations are made in a mountain, of which the top and fides are of granit, the granit does not become more beautiful and folid as we defcend deeper, but changes its appearance infenfibly, till it is at laft loft in a rock of a quartzeous nature. To thofe who attribute the formation of all granits to water, it is objected that they do but remove the queftion a little farther back; for it will ftill be enquired what agent wrought, and what quarry furnished the fragments which conftitute granit; hence they will be obliged to feek for the origin of the great maffes, whence the fragments were detached, fince water cannot produce them. This objection, if it fhall be determined on weighing the oppofite probabilities, that granits are the product of aqueous cryftallization, will eafily be answered; for every difcovery of man does but put back the chief queftion. Religion, not philofophy, unfolds ultimate causes.

This article is animated with all the fpirit of Buffon. It fhews that old age has not clouded his imagination nor enfeebled his eloquence.

He next confiders fand-ftone, which is compofed of fmall grains of quartz joined together by the intervention of water. The cement which connects them may be conveyed in two ways, by water oozing through, or by vapour, tho in fome of the inftances quoted in fupport of this affertion, as in thofe from M. Laffone, the induration feems to have been occafioned by the air and not by the acceffion of any cement. Pure fand-ftone confifts of quartz only; the other forts are contaminated by metallic, and ftill more frequently by calcareous admixtures; pofition of the great maffes of fand-ftone; remarkable inftance of fand, conveyed no doubt in vapour, penetrating through glafs; varieties of fand-stone; different colours it affumes; the newly difcovered crystals always contain a great deal of calcareous earth, whence their rhomboidal form; fuch are the other principal topics difcuffed in this chapter, wherein the author may fairly be faid to have ftruck entertainment out of flint.

Clay and glaife, or impure clay, derive their origin from vitreous fubftances mollified and attenuated by the action of the moist elements. Clay, either in its proper form or that of flate and fchift, ought to be regarded as the firft earth: the ftrata that were firft depofited by the waters, confift of this earth; the irregularity of its ftrata are owing to this early origin, for they refted upon the vaults of caverns, which afterwards fell in. The different forts of clay are defcribed, and the causes of the difference affigned. The following obfervation is brought to fhew the influence of clayey ftrata

on

a vegetation. "In fummers remarkably dry, fuch as was that of 1778, trees lofe almost all their foliage very early in September, in foils of fand, chalk, tufa, and compounds of thefe, whereas in countries lying upon clay, they preferve their verdure and leaves; it is not even neceffary that the clay fhould be immediately under the vegetable earth, for in my garden, where the mould, which is three or four feet in depth, refts upon a bed of calcareous earth, fifty-four feet thick, the trees were as green after two months of drought as those in the valley; this happened because the lime-ftone refting upon clay, allows the watery exhalations to arife thro its perpendicular fiffure, which exhalations conftantly moiften the mould at the furface."

In the following articles, in which modifications of calcareous earth are defcribed, their origin is imputed to the collected fragments (detrimens of marine productions. That common but puzzling phænomenon, the prefence of pieces and ftrata of flex, is thus explained: "the cretaceous powder was mixed with vitreous and filiceous particles, at the time it was tranfported and depofited by the waters; after the formation of thefe calcareous ftrata thus mixed with filiceous molecules, the, water penetrating through them, took up thefe particles and depofited them between the ftrata, where their affinity united them, and where they moulded by the cavities and intervals in the ftrata." Calcareous matters, of primary and fecondary formation, may be diftinguished by the abfence of fhells and impreffions of fhells from the latter, by their pofition at the foot of the hills of which the ancient beds having been attached by frost and water, have afforded powder and gravel for the currents to carry away and ftratify. Three kinds of ftrata formed at different periods and by different caufes are defined; 1. The primitive, containing fea-fhells. 2. The fecond, containing river or terreftrial fhells, and, 3. thofe which exhibit no traces of fhells, but are formed of the fragments of the two former. By thefe fuppofitions M. de Luc's objections to the origin of calcareous matters, as above affigned, feem to us in a great measure to be removed. Several marks are there given, by which, if they be juft, an ancient ftratum may be easily recognized. We have afterwards an account of thofe quarries which afford ftone, that is liable to receive damage with the caufe of this phænomenon, an account of the petrifying juice, which is nothing but very fmall particles carried by water and depofited in the interftices of the grains, and the different appearances of the beds as they lie higher or lower, with the reafons of the difference. All alabafter has been formed by depofitions of particles carried away

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from

from higher ftrata by water; under this denomination are ranked ofteocalla and incrustations in general. With respect to marbles, all that has been faid of primary or fecondary lime-ftones may be applied to them; Nature formed them in the fame way; the first piled up heaps of thells and madrepores; thefe the afterwards reduced to fand or gravel, which were depofited in horizontal beds. They acquired their first degree of confiftence from their mutual attraction, which was afterwards greatly augmented in the lower ftrata by the infiltration of petrifying juice inceffantly dripping from those placed above. Thus it happened that the hardest lime-stone as well as marbles always lie lowermoft, and the greater thickness there is of ftrata above, the denfer are those that are fituated below." Thefe chapters, and the following on gypfum and compounds of calcareous and vitreous earths, abound with new, ingenious, and apparently juft obfervations. A diftinction between gypfum and plaifter of Paris is founded, with whatever propriety, on the prefence of marine and nitrous acids, befides the vitriolic, in the latter. Some experiments of a M. Nadaulf are quoted, in fupport of this opinion, but they do not feem to have been fo conducted as that a cautious reafoner would venture to deduce a conclufion from them.

Vegetable earth is found in two ftates, viz. in that of mould, and of mud. The ftratum of mould is always thicker in úneultivated than cultivated fpots. This earth produces. moft regularly fhaped foffils, and even the diamond itself. The granular and marthy ores of iron and martial pyrites derive their origin from mud; here the author's reasoning is unufually lame and unfatisfactory."

The first volume concludes with the hiftory of pit-coal, which is given at great length as it occupies above a hundred pages. Pit-coal is faid to be entirely formed of the folid fragments and liquid oil of vegetables, indurated by the admixture of acids. From peat recent and without mixture of bitumen one may proceed to fuch as is older and bituminous, and from wood converted into coal (charbonnifié) to real coal: confequently coal is nothing but vegetables preferved by bitumen. After having combated the opinions of two French authors, on the origin of coal, M. Buffon proceeds thus, in order the better to understand the production of coal, and unfold its compofition, it is neceffary to trace the decay of vegetable substances both in the air and under water: when lying on the ground, they ferment, and if the accumulation be large, they will take fire, and the refiduum will be no longer combustible, after this diffipation of the igneous particles. But under water

the

the decompofition is far flower, the fermentation infenfible, and the vegetable fubftances will long, perhaps for ever, preferve the combuftible principles, which they would foon have loft if they had lain in the air. Peat exhibits this first decompofition of vegetables under water, as it does not in general contain any bitumen and yet will take fire, as alfo do those black fhining fpecimens of foffil wood, which are fo decayed as not to be diftinguishable, and yet have retained enough of their inflammable principles to burn, but afford no odour of bitumen. But when this wood has been long buried or under water, it becomes bituminous by the combination of acid with its oil. And if it happens to be under ftrata containing pyrites or vitriolic acid, it becomes pyritous, and yields in burning a strong smell of fulphur.

"If we trace this decay of vegetables upon land, we shall find that plants and tender kinds of wood afford a black mould, juft like that which is often found in their ftrata above coal-mines; while the harder forts of wood, as oak and beech, retain their folidity, and form strata of foffil wood frequently to be feen over coal-mines. In fhort, this mould in time becomes mud or vegetable earth, both which, if they decay flowly, will retain part of their combustible principles: the mould, as it is converted into mud, is turned red or yellow by the diffolution of the iron, which it contains: it also becomes unctuous and ductile in confequence of the developement of its oil; now all mould as well as mud retain more or lefs combuftible particles, and what is at this day found in the form of peat, foffil-wood, and pit-coal, is nothing but ancient ftrata of trees, mould and mud."

Having in this manner confidered the nature of coal, inveftigated its origin, and at the fame time fhewn that its formation is pofterior to the exiftence of vegetables, the author examines the fituation and extent of its veins, and enumerates the places where it is found. He concludes with fome obfervations on its ufes and preparations.

We have not room, at prefent, to accompany him through the fecond volume. We have been diffufe in our abridgement of the firft, on account of the refpect with which all M. Buffon's opinions are received in his own country, where we have no doubt but the prefent work, like his preceding productions, will become a ftandard book, to be quoted and commented on by French authors, who, feem in many inftances, by a strange infatuation, to prefer his authority to the proofs of other writers.

The general reflections that have occurred to us during our perufal of the prefent treatise, muft likewife be deferred to a future number.

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MONTHLY

MONTHLY

CATALOGUE.

[For JANUARY 1785.]

MISCELLANEOUS.

Art. 14. The Dramatic Hiftory of Mafter Edward, Mifs Ann, and Others, the Extraordinaries of thefe Times. Collected from Zaphaniel's Original Papers, by George Alexander Stevens, Author of the celebrated Lecture upon Heads. To which are prefixed, Memoirs of the Life of the Author. A new Edition, illuftrated with Copper-plates, 12mo. 4s. Murray. 1785.

It would be inconfiftent with the plan of our work to bestow a very large attention upon a performance long fince publifhed, and now revived. The perfons alluded to in the title are Mr. Shuter and Mifs Nancy Dawfon. The reputation of the author is sufficiently known, and he has drawn a numerous train of admirers. While his compofitions bid defiance to all the laws of fyftematical criticism, it is impoffible to deny him the praise of humour and originality. To the edition before us is now prefixed a sketch of the history of the author.

Art. 15. An authentic Letter from a difconfolate Member of Parliament to his unfortunate Son, lately convicted of robbing the Poft Office; London. Is. 6d. Dodfley. 1784.

The late abuse of franking is expofed in this publication with a good-humoured feverity. There is a good deal of wit, much general, and fome perfonal fatire in this performance; which, upon the whole, rifes above the mediocrity of the general run of such temporary jeux d'efprit.

Art. 16. The Spartan Manual, or Tablet of Morality: being a genuine Collection of the Apophegms, Maxims, and Precepts of the Philofophers, Heroes, and other great and celebrated Characters of Antiquity; under proper Heads. For the Improvement of Youth, and the promoting of wifdom and virtue, 12mo. Dilly. London.

This little work is publifhed with the view of advancing the interefts of virtue and morality. Its defign, accordingly, is to be ommended. But its execution is greatly defective; and the vanity :f the compiler in his introduction does not ferve to imprefs the readwith any favourable opinion of him. He conceives too extraagantly of his piece, when he affirms that nothing of the kind ver poffefled fo high a title to credit and authority. The fentences and maxims he holds out, have no doubt, the fanction of antiquiBut antiquity was not always in the right; and, if he had been reallyl earned, he might, with the greateft cafe, have extracted fomething more perfect from the ftores of ancient wisdom.

ty.

Art. 17 Thoughts on the Slavery of the Negroes. 8vo. 6d. Philips 1784.

This little tract, in which the author very feelingly and ably pleads the caufe of the oppreffed negroes, appears to be a fhort abridgment