brown, and black brown. It is flesh red, blood red, brick red, carmine red, which paffes into rofe red, light violet blue, Pruf⚫fian blue, and indigo blue.' In fhort, what colour of the rainbow is denied it?

Its irregular forms, however, are, if poffible, ftill more various; for it is found maffy, diffeminated, in rounded fragments, in grains, in lamina; it is ftalactitic, globular, reniform, tubulated, fpecular, pectinated, cellular, fpongiform, hollow from impreffions, perforated, carious, and amorphous." We may now exclaim, Is there any form in which it is never found?

Its crystals, however, are all derived from fix-fided prisms, terminated by fragments of the fame number of fides; but as no angles are measured, or proportions itated, no precife idea can be formed of the modification; and were they not distinguished by internal characters, they might be confounded with the carbonates of the barytes and lime, and with other cryftals. The fize of the cryftals varies from very fmall to very large. ' The pfeudomorphique cryftals of quartz are various. It is found affuming the form of four-fided tables, lenfes, rhomboids, cubes, octohædrons,' &c. &c. Nor are the Germans provided with any rules for diftinguishing thefe from the true cryftals, except the accidental roughnefs of their furfaces.

Its luftre varies in degree, and is fometimes the vitreous, and fometimes the fat luftre.

The fracture varies from the conchoidal with fmall cavities," to the fplintery with large fplinters.' Sometimes it is imperfectly lamellar;' fometimes fibrous, with coarfe fibres.' No one can defire greater latitude than is here allowed him; for, befides the great choice of general expreffions, a moft unfcientific confufion is produced by confounding the fracture with the fruc ture of the fubftance in queftion; the lamina and fibres refer to ftructure, the conchoids and fplinters to fracture.

Its fragments are indeterminable, with fharp edges, and rarely rhomboidal. This might have been of fome ufe, if the fragments of most substances were not indeterminable. 'It is rarely granular: that character, of courfe, can be of little ufe in inquiring after quartz, though the enumeration of its occafional occurrence may refcue fome folitary fpecimens from exclufion. It might have been usefully announced among remarks, but its intrufion into the characters is impertinent.

It is commonly tranflucid, feldom femitranfparent; for (mark the fubtlety of the diftinction) a trifling increase of transparence elevates it to the more exalted rank of rock cryftal.

It is hard.' So are almost all minerals-fo is Suffolk cheese. The question is, how hard-what ftone will it fcratch, and what will fcratch it?

"It

It is fragile-It is middling heavy.' Almost all minerals are fragile, and nine tenths of ftones are middling heavy. The abfence of these most common attributes might convey a ray of illuftration, but, their prefence can characterife nothing.

Such are the external characters of Quartz, in which it appears, on a complex view, to differ from itself, and in the detail, to refemble almost every other mineral substance.

He who can diftinguifh quartz by the enumeration of these nullities, muft poffefs an intuitive mineralogical fagacity, surpassing in marvelloufnefs all the legendary fables of necromantic kill. The famous divining rod is ftill, we believe, reforted to occafionally for discovering the direction of metallic veins; and if the ftudents of Germany poffefs fuch acutenefs as to comprehend and profit by the defcriptions of minerals presented in their books, we fhould be induced to fuppofe that the acquifition of a divining rod was an indifpenfable requifite for unlocking the arcana of the fcience, and would impute our own indocility to the want of fo useful an inftrument. But the grofs errors into which those who are most familiarized to the external characters are frequently betrayed, and the admitted impoffibility of acquiring mineralogical knowledge from books, lead us to prefume, that even the most zealous will abate their confidence in thefe characters, and feek for more unerring and unequivocal criteria in the ftructure of minerals, in their electric and magnetic relations, in their refractive and phofphorefcent phænomena, in the effects of heat and the more fimple chemical tefts; that the relative hardness expreffed, by specifying what minerals scratch, and what are fcratched by a given fpecies, will fuperfede the present vague defcription of hardnefs; that the exact specific gravity fet down in arithmetical cyphers, will fupply the place of middling heavy' and its coadjutors; and that future obfervers will employ themselves in thefe inveftigations, inftead of balancing a ftone in their hands, or feeling if it is cold.

In their cenfures of foreign mineralogifts, the Germans seem actuated by a genius which, feeking to embrace the boldeft outlines of their science, defpifes the littleness of detail, and the drudgery of accurate investigation. While they contemptuously fneer at him who meafures the angles of a cryftal, or feeks to difcover the nature of a mineral, by obferving the direction of its natural joints, they endeavour to fyftematize chaos, and, inftead of recoiling from the endlefs admixtures, gradations and tranfitions of rocks, feem to expect that fubftances the most diftinct fhould iffue from elements the moft confufed, and clafs them with as much decifion as if they were defined by regular form and unadulterated compofition. Yet we often find them inconfiftently

inconfiftently receding from this daring plan, and gratuitously beftowing on a fhade of colour that power of conftituting fpecies, which they refufe to effential, integral difference, and decided variety of geological relation.

Thus quartz, if tranfparent, is rock cryftal; if only translucent, is quartz. Tinge it purple, and it is amethyft: Let it be reddish or whitish, and rather opaque, and it is milk quartz: Let its fracture be splintery, and it becomes hornftein: Let it be conchoidal, and it is flint: If mamellated or invefting, it may be chalcedony: Let it be irridefcent, and it is opal; add a minute portion of iron and argil, and it is jafper: Let the iron be rather more than ufually abundant, and it is eifen keifel. Yet all thefe, and more, are quartz: their grand conftituent is filicious earth. Every teft exerts on them a fimilar agency; every analyfis gives the fame refult.

Nor is quartz the only mineral unneceffarily fubdivided. The zircon and hyacinth differ only in a fhade of colour; the chryfolite and oliven do not differ at all. The pyrop, which has lately exfoliated from the clafs of garnets, has no difference but fuperior beauty. The emerald and beryl differ only in colour; tourmaline and fchorl are precifely the fame. Nor are these frivolous fubdivifions confined to the combinations of earths with earths, where the uncertainty of analysis affords an excufe for confufion; for they extend to the combinations of acids with earths and with metals. Werner divides the phosphate of lime into two diftinct fpecies, under the names of apatite and spargelftein. And in the recent tables of minerals, publifhed by the enlightened Karften, we find the combinations of lead and phofphoric acid divided into four fpecies, folely on account of variations of colour, which the names affixed to them defcribe.

Though thefe obfervations are not strictly confined to Emmerling, they are strictly applicable to his performance; for no fyftem can be more vicious than the one he has adopted; there is no imaginable perplexity on which he has not blundered--no lapfe of inaccuracy into which he has not flid. Apparently unacquainted with either French or English, his attempts to diplay a knowledge of thefe languages, deform his lift of fynonymes with the moft ludicrous blunders; and, in his Second Part, he feveral times misunderstands Haüy, in a manner that bears the appearance of ftudied perverfity. Fortunately for foreign authors, he feldom honours them with his attention, but, with very pardonable prédilection, felects his authorities from among his German brethren. Some partiality is apparent in his appreciation of their merits. In the First Part, Werner rifes lord of the afcendant; but, in the Second Part, his declining glories are exVOL. III. NO. 6. tinguished

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tinguished in the blaze of another luminary. Karften, for reafons to us unknown, selected Emmerling's first edition as the text-book to his tables, and occupies a broad column, by repeating, after the name of each fpecies, the words Emmerling's Mineralogie, with a reference to volume and page. The vanity of any man might be titillated by applaufe from Karften; and Émmerling, in his Second Part, has elevated him as high as his feeble powers would permit. He now finds Karften's arguments are unanswerable, his pofitions irrefragable, and his affumptions juft. In cafes of conteft, Werner, and every one else, must give way; and much extraordinary incongruity is introduced into the work by this change of its tutelary genius.

The arrangement of a fyftematic work firft attracts the reader's attention. Though the method followed in arranging the minerals in the first part of this book, be totally different from that adopted with reference to the fame fubftances in the fecond part, there are fome general cenfures to which in our opinion they are equally liable.

The first part approaches nearer to the method of Werner, than to any other fyftem we are acquainted with; and the fecond part deviates only in a few unimportant tranfpofitions from the arrangement of Karften's tables. Both of thefe celebrated men affume the compofition of minerals developed by analyfis, as the bafis of their fyftem. They divide their minerals into orders, named after the earths, and generally clafs them according to the predominating component. Aware, probably, of the prefent imperfections of analytic chemiftry, Werner does not rigidly regulate his claffification by the refulting proportions of earths. He allows his judgment to be guided by imaginary families and gradations; and commonly places minerals in the clafs of the carths whofe particular characteristics they feem to bear, without attending to predominance in quantity. Thus, we find Werner claffes jafpers and opals among the argillaceous genus, though the opal contains no argillaceous earth at all, and the jafper only about 20 per cent., filex being the grand component of both. Thus he alfo places in the filicious genus, the fpinel, the faphire, and other gems which contain no filex at all.

With greater reliance on analytic refults, Karften has regulated his fyftem by them, as clofely as the nature of the fubject would permit. Yet even Karften has been constrained to make many fingular deviations from the ftrict rule of proportion. Clay, which it would be difficult to exclude from the argillaceous genus, generally contains twice as much filex as argil. Argillaceous thiftus, wakké, and bafalt, are all nearly fimilar in the disproportion of the earth under which they are claffed. In the magneúan

genus

genus there are only two inftances in which magnefia is contained in a larger proportion than any other earth; and it is well eftablifhed, that some varieties of talc contain no magnesia at all.

We have, in a former paper, ftated at length the arguments which appeared to us decifive againft arranging all minerals by the refults of analysis: those objections were confined to the combinations of earths with earths, where minerals of the moft ftriking diffimilarity appear compounded of the fame elements, and in nearly the fame proportions; and where differences, the most important, refult from caufes that have hitherto eluded refearch. It appears to us, that no argument can more strikingly illuftrate the pofitions we endeavoured to lay down, than the incongruities which deform the celebrated fyftems we have quoted. In the one, minerals without filex are jumbled with those in which filex is predominant, to the perplexity of the ftudent, and aftonifhment of the proficient. The other commences with a steady obfervance of proportion, which is at once wantonly relinquished; and the deviation from regularity becomes more deceptive, because unexpected. Werner places the chryfoberyl at the head of the filicious genus; of course, it is concluded that filex predominates. Far from it; that mineral contains 71 per cent. of argil. Jafper is at the head of the Argillaceous genus, and it contains 75 per cent. of filex. Bol is placed at the head of the Magnefian genus, and it contains 19 per cent. of argil, 47 of filex, and only fix of magnefia. Utter confufion feems preferable to arrangements, where the appearance of order is fo extremely fallacious, where the species are not what the generic denomina tion declares them to be, and where thofe who induftrioufly ac quire a knowledge of the system are only rewarded by an accumu lation of error.

In imitation of Werner, the diamond is allowed, by Emmerling, to conftitute a separate genus among earths and ftones. As there is no point in chemistry more clearly determined than the compofition of the diamond, we viewed this arrangement with fome furprife, till we perufed the explanatory observations; in which we found, that fo faint a rumour of the recent difcoveries has yet reached Mr Emmerling, that he may be excufed for har bouring an expectation that a more noble origin might yet be af figned to the diamond than the one Sir Ifaac Newton prophetically allotted it. As Karften has judicioufly placed it among combuf tibles, we hope that, in Mr Emmerling's future volumes, he may correct the position of the diamond, and enlarge his account of it.

In the next article, Mr Emmerling's difplay of fynonymes is, as ufual, unfortunate. The English name of the zircon or jar

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gon