« ForrigeFortsæt »
those of all who engage in theological controversy, which is emimently useful in rousing men to the utmost exertion of their faculties, he is promoting his own excellent purposes, and providing for the prevalence of truth; in his own due time; and in this general prospect we ought all equally to rejoice.
• It becomes us, however, to confider, that they only will be entitled to praise, who join in carrying on the defigns of Providence with right views of their own; who are actuated by a real love of truth, and also by that candour and benevolence, which a sense of our common difficulties in the investigation of truth most effectually inspires. A man who has never changed an opinion, cannot have mucb feeling of this difficulty i and therefore cannot be expected to have much candour, unless his disposition be uncommonly excellent. I ought to have more candour than many others, because I have felt more than many can pretend to have done, the force of those obstacles which retard our progress in the search of truth.
"With much tranquillity, a tranquillity acquired by habit, but more approaching to a pleasing alacrity, than to any uneasy apprehension, I thåll wait the issue of the present controversy ; freely retracting whatever I shall be found to have advanced with too little consideration ; moderating any thing on which I fhall appear to have laid too much stress, and urging with the greatest freedoin every pew argument or illustration that may occur to me, till I shall have nothing of consequence to alledge. After this I shall no longer reply to particular opponents, but content myself with making such corrections and improvements either in my History, or my intended Vicw of the doctrine of the first ages of the cbriflian church, concerning the person of Christ, as I may see necessary; fubmitting every thing to the judgment of those who may think proper to give any attention to the subject.'
It feldom happens, whether we chase to afcribe the phenomenon to nature or to habit, that the same mind, which has obtained important success in the pursuit of speculative science, is qualified to produce the beauties of the imagination. Accordingly, though, from the solidity of his judgment, we are satisfied that our author is capable of exhibiting a inuch more polished and regular work, than any he has yet given to the public ; yet certain it is, that in aiming at the height of sublimity, or the finer touches of passion, he would fail in the attempt. But there is an interesting language, that comes from the heart, and with which the fancy of the writer has hothing to do ; and of this the extract we have produced indisputably shows Ds. Priestley to be mafter.
F O R E I GN LI T E R A TU R E.
Buffon's Natural History of Minerals.
one who has enquired, however superficially, concerning the productions of the material world, must be anxious. to learn how this venerable historian of Nature has found the means of adapting his eloquence and his theories to the minutiæ of mineralogy ; for in his former volumes he' had treated most of the general topics which alone would seem to allow his talents for fine writings much scope. Let us see how he has found or created space for the exertion of his genius. He begins with considering the cause of cryftallization; or, as he denominates it, la figuration, a term new alike to the French and the English languages, and we think unnecessary, since it is not more expressive than the old one. And here, in the very front of his work, he again introduces to thy notice, be not startled, good reader ! his organic molecules, or, as he now frequently chuses to call them, organic parts. He divides fossils into three classes, one comprehending such products of the primitive fire as have not changed their 'nature, viz. roc vif, quartz, jasper, feld-spath, schoerl, 'mica, fandftone, porpliyry, granite, with such substances of original or fecondary formation as are not calcinable ; and besides these, vitrifiable sand, clay, schist, slate, and whatever comes from the decomposition of primitive matters attenuated, dissolved, or any way altered by water : another containing bodies that have a second time undergone the action of fire : these two classes belong to inorganic nature (la nature brute) as they feldom or never bear any marks of organization ; and a third and last class comprizing calcinable substances, vegetable earth, and every thing formed of the spoils of animals and vegetables by means of water; these are, the several modifications of calcareous earth, that thin stratum of mould which almost every where covers the surface of the globe ; as also peat, foffil-wood, coal. In this class, observes the author, may be perceived every gradation between brute matter and organized substances ; this intermediate matter, partly brute and partly organic, serves alike for the productions of Nature in her two empires of life and death, for vegetable mould and calcinable bodies contain far more organic particles than those substances which have been produced or changed by fire ; these particles, ever active, have made Heep impreslions upon passive matter; they have elabo
rated all its surfaces, and sometimes penetrated into it. Wa' ter developes, dilutes, transports and deposits these organic elements on brute matter : thus most regular fossils owe their form to the combination of this active matter with the wa. ter, which conveys it. The productions of organized Nature, which, in the state of life and vegetation, represent her power and constitute the ornament of the earth; continue after death to be the noblest part of formless Nature ; the spoils of animals and vegetables preserve their active organic molecules which impart to påffive matter the first rudiments of ore ganization by bestowing on it an external figure. Every foffil form has been elaborated either by these molecules proceeding from decayed organized bodies, or by those which existed before their formation. Thus minerals, with a regular shape, are more or less connected with organic Nature, and there exift no substances totally brute, except those which bear no mark of crystallization, fors like every other property of matter, organization has its shades and dea grees, of which the most general and moft diftinct characters, as well as the most evident refults, are life in animals, vegetation in plants, and figuration in minerals.”
After having made fome remarks on the growth of organized bodies by intus-fufception, and the enlargement of foffils by the juxta-position of regularly-fhaped laminæ infia nitely small and Nender, he observes that the formation of each thin lamina. is a true lineament of organization which cannot be traced on the constituent parts of each mineral but by organic elements. Is it not likely, he continues, that Nature, which so often works matter in its three dimenfions at once, should still more frequently labour it in two only, employing but a few.organic molecules, which, being in this case overburthened with brute matter, can arrange the surface only, without being able to penetrate internally and elaborate the basis, and consequently to inform the mass either with vegetable or animal life. And although this task be fimpler than the former, since it is more eafy to fineer (effleurer, how shall we translate this word ?) matter in two dimensions than to work it in all at once, yet Nature employs the same means and the faine agents. The penetrating power of attraction, combined with the expansive force of heat, produces the organic molecules, and fets brute matter in motion, determining it to such or such a form, as well internally as externally, when it is wrought in all dimensions at the fame time, and thus are formed the germs of animals and vegetables : but as in fossils every lamina iş wrought but in two dimensions by a certain pumber of molea cules, its furface only can receive any regular "thape, which ENG. Rev. Jan. 1785. Vol. V.
elaboration of shape is undeniably a first line of organiza-
prefence of organic molecules in cryftals, and of their abfence from the fame body in a rude fhape : we need not take the trouble to remind them how experience has fhewn that almost any substance may be obtained in a regular form by proper management. Such confiderations ought to be as far removed from the perufal of M. Buffon's theories as of poetical fictions.
After this view of the general theory, let us take a short furvey of the moft remarkable particulars. As the author proposes to confider fossils in the order of their antiquity, his notions concerning the formation of the earth lead him, as. we have already stated, to treat first of the products of the ori ginal fufion, and then of its various modifications in fucceflion. The glaffy fracture, hardness and infusibility of quartz fhew it to have been the primordial glass, and to be the matter of which the folid nucleus of the earth confifts but as it cooled it must have exfoliated in and become cracked and tarnished on the surface, hence mica; iron the moft refractory of the metals, next was precipitated from the atmosphere, and occupied some of those cavities which were formed on the surface of the cooling mass; this metal, difcolouring the primitive quartz, formed jafper, as also feld. fpath * schoerls, which have in like manner quartz for their basis, but were more modified by the condensed impuriies.
Quartz is found in three different states ; first, in large maffes, hard, and without moisture, produced by the primitive vitrification. Secondly, in small pieces that flew off in the first æra, during refrigeration ; in this form it enters in
See his Epoques de la Nature.
to the compofition of granít, &c.; and, thirdly, as altered by vapours of the earth, or the infiltration of water. Pris mitive quartz is dry to the touch, that which is altered is fofter, and what serves as a matrix for: metals is generally unetuous.
Jasper differs from quartz in being more opake, and having a fracture less smooth is found more rarely, because metals exist in few places only. Account of a curious mountain in Lorrain, which exhibits jasper running in undulating veins among quartz; thefe veins represent the funnels through which the metallic exhalations arose, for they are of various colours, and the quartz seems to pass gradually into jarper.
Mica is cotemporary with the two former primitive glasses, but is never found in large masses. Talc differs from it in being softer to the touch, and in being found in larger laminæ, and sometimes in strata. All talc, however, was once mica; it has only been more exposed to the action of water, whence its unctuosity. Mica formed originally the external cruft of the globe, under which quartz and jasper were annealed, and which being itself suddenly exposed to the influence of cold, was split into spangles. Feld-spath and fchoerl
, continuing longer in a state of fufion, received more heterogeneous substances, some of which were faline, as they condensed; whence their fuhbility.
The fracture of the former fpathaceous, it is no where found in great masses. Schoerl is itfelf a feld-spath, in which quartz the common base is mixed with more extrane
We have, in the next place, an enumeration of the compounds formed by these original glasses. Porphyry is faid to confift only of jafper, feld-fpath, and schoerl. It is compared with granit; notice is taken of the superior duration of monuments of porphyry above those of granit. A defcrip. tion is given of the various forts, together with severe strictures on Mr. Ferber's enumeration of those of Italy. A distinction is made between porphyries of primitive and fem condary formation.
M. Buffon attempts to explain the formation of granit from the hypotheses already mentioned, togetlier with the fusibility of felt-fpath and schoerl. When the fcales and fragments of the first glasses had exfoliated, and lay loose upon the surface in a folid, or nearly solid state, the two laft ran between their interstices, and bound them together like a cement. In this article a curious observation is brought
forward, which, according to the author, has been entirely neglected by other mineralogists, and which, it must be own-,