the earth; yet the minutest of his works, for their exquifite fymmetry and delicacy, are equal evidences of the boundless fkill of the divine Artift, who hath furnished us with no less matter of meditation and wonder in the conformation and instinct of the most contemptible infect, than in the attributed fagacity and unweildy bulk of the elephant.

"That in nothing

Well might the immortal naturalist say, more is seen the workmanship of nature (God) than in “the artificial compofition of thefe little bodies," which in his contemplation on the body of a gnat he fo elegantly illustrates; “Ubi vifum pretendit? Ubi guftatum applicavit ? "Ubi oderatum inferuit? Ubi verò truculentam illam, et portione maximam vocem ingeneravit? Qui fubtilitate pennas "adnexuit? Prælongavit pedum crura? Disposuit jejunum "caveam uti alvum? Avidam fanguinis, et potiffimum humani, "fitim accendit? Telum verò perfodiendo tergori quo fpiculavit ingenio? Atque ut in capaci cum cerni non poffit exilitas, ita "reciproca geminavit arte, ut fodiendo accuminatum pariter "forbendo que fiftulofum effet." (Pliny.)

If Pliny had been acquainted with microscopick discoveries, where would he have found words to exprefs his admiration at Dr. Hook's affertion; "That if a large grain of fand was "broken into 8,000,000 of equal parts, one of them would "exceed the bigness of those creatures, who were fo exceed"ing small, that millions of millions might be contained in one drop of water !”

If we defcend from the surface of the earth, we shall likewise find in her bowels endless ftores of foffils, petrifactions, minerals, and metals, to fupply mankind with the means and materials of every ornament and conveniency in which we may, as through a glafs darkly, behold the fecret operations of him that worketh all in all, both in the heart of man, and in the bowels of the earth! "Great and marvellous are thy "works, O Lord God Almighty! In wisdom haft thou made "them all the earth is full of thy riches !"

It is very probable that the nature and ufe of Metals were not revealed to Adam in his ftate of innocence: the toil and labour neceffary to procure and use those implements of the iron age could not be known, till they made part of the curfe incurred by his fall: "In the fweat of thy face shalt thou

"eat

"eat bread, till thou return unto the ground; in forrow shalt "thou eat of it all the days of thy life." (Genefis.) That they were very early discovered, however, is manifeft from the Mofaick account of Tubal Cain, who was the first instructer of every artificer in Brafs and Iron; and being the fon of Lamech, who was the father of Noah, must have been fuch an instructer Anno Mundi 1,200, or thereabout. Whether this is the fame perfon as in the Heathen mythology is called Mulciber, or Vulcan, who was the god of fubterranean fire, and efteemed the president over Metals, it is not effential to our purpose.

It has been long difputed whether Metals are generated, or were all originally produced at the creation: whether they admit of germination, or augmentation, like animal or vegetable bodies, or whether they proceed from an accumulation and cohesion of metallick particles; or by what other means they were formed and produced.

;

The doctrine of the alchymift maintains, that they proceed from a certain Primum Ens, or first feed of Metals, which they say is a kind of moist vapour or Gas, that changes the earth and juices it meets with in a vein into a mineral body or substance and thence converts the Minerals into Metals or Ores by a continued fermentation and elaboration in the Mines, caused by the Archeus or heat that acts on the veins, as it proceeds from the center of the earth; it afferts also, that different Metals are produced conformable to the time and degrees of fermentation which the Mines have undergone; and partly by the purity and fuitablenefs of the veins, or the earth in them, which they suppose are as matrixes to contain and nourish Metals in embrio; fo that in the space of a thousand years, it feems, a Metal is generated and perfected de novo, according to the concurrent causes, such as the impregnation of the Archeus, or the like. But this doctrine of Mineral fermentation is very properly denied to have any existence, by the accurate Boerhave, who, in his Hiftory of Fermentation, declares it to belong only to the vegetable kingdom; for he says abfolutely, "This inteftine motion can be "excited in vegetables only;" and for Minerals, he does not remember that any fermentative motion has been observed therein: so that I think we may with full propriety express what is meant in the term fermentation, by effervefcence, which different admixtures of Mineral particles may momentarily excite ;

and

and which really conveys a separate sense and meaning, from the true natural operation of ferments.

Others will have it, that all Metals and Minerals were at first created in the very fame ftate and nature in which they are always found, without undergoing any kind of alteration. The most common opinion among the Miners in Cornwall is, that crude immature Minerals do nourish and feed the Ores with which they are intermixed in the Mines; and that the Minerals themselves will, in process of time, be converted into Ores productive of thofe Metals, to which they have the nearest affinity, and with which they have the greatest intercourfe. This, however, is but the common opinion. Those of moft experience feem to have a contrary notion of the matter, and yet differ among themselves. We apprehend the best and moft plaufible reafons that can be advanced, are those which are nearest at hand, are moft obvious to our fenfes, and are deduced from observation and experience; and therefore, without animadverting on the different opinions abovementioned, we shall proceed to communicate our own thoughts on this controverted subject.

It is reasonable to conclude, that Metals were made and implanted in veins at or very foon after the creation of the world. Tin Ore will peculiarly evince the juftness of this conclufion; for it is frequently found, in its richest and purest state, in large fpots and bunches in blocks of stone of the most hardened confiftence, fuch as Granite, Elvan, and the like, which have been above the furface ever fince the firft induration of folids, have experienced no revolution, nor been water-charged with metallick particles, unless from the clouds of heaven. Perhaps it has been primarily fo with moft other Metals, as their usefulness was discovered to man before the methods of finking deep into their proper niduffes were at all known. In other countries, where Metals may be more generally diffused, it has probably been found as I fay; and from the beginning, these metallick distributions may have experienced a decay and alteration by the action of the different elements upon them, according to their specifick induration or laxity.

I have before obferved, that Metals are fubject to a degree of fluctuation, in common with all matter; and that they approach to, or recede from, their ultimate period, or degree of perfection, either quicker or flower, as they are of a

greater

greater or less folid and durable frame and conftitution. In favour of this opinion, it is found, that the Ores of Copper and Lead, though rich and folid in nature, yet by a long infolation, or exposure to the fun and weather for fome years, lofe much of their Metal: and alfo, that those Mines which abound with a rich mature Copper Ore, do, near the surface, at least immediately over the body of the Ore, commonly contain a rust, tincture, or spume of Copper, resembling Verdigreafe; which seems to be an Ore in a declining ftate, being elevated by an effervefcence in the bowels of the Mine from that fulphureous body of Ore which often lies under it, and to which it did belong at first, and was united with it, till some intervening caufe occafioned fo vifible an alteration in the Ore of one and the fame Mine.

It seems to me that in every Metal there is a peculiar magnetism, and an approximation of particles fui generis, by which its component principles are drawn and united together, particularly the matters left by the decompofition of the waters paffing through the contiguous earth or ftrata, and depofited in their proper nidus; till, by the accretion of more or lefs of its homogeneous particles, it may be demoninated either rich or barren.

That Ores, and even virgin Metals, are or may be formed in this manner, seems manifest from a method now in use, of extracting Copper from waters ftrongly impregnated therewith: Iron which has lain fome time in fuch water, is found on examination to be greatly corroded, and to have Copper formed in its stead, either adhering to the Iron, or funk to the bottom of the vessel, in form of ruft, and fometimes even in small grains of a complete metallick appearance.

This Copper and ruft on being smelted with a reducing flux, fometimes produce above three-fourths of their weight pure Metal. The water generally used for this purpose is that which is left by lotions of black Tin, intermixed with Copper, after it has been calcined in the proper furnace, commonly called a Burning-Houfe. The Copper contained in this water, is kept in folution by an acid; and this acid having a greater affinity with Iron than with Copper, on the immersion of Iron, quits the Copper to join with the Iron; by which means a precipitation enfues, in the manner just mentioned. This process may at any time be evinced by the following experiment. Diffolve

thin plates of Copper in Aqua-fortis, and you will have a clear liquor of a fine blue tinge: on applying to this thin plates of Iron, the acid, quitting the Copper, will precipitate it in the manner before described, as Copper would have done by Silver, had it been first diffolved in the menftruum; and as fixed alkali will do by the Iron, after it has diflodged the Copper.

From this we may reasonably infer, that water, in its paffage through the earth to the principal fiffures, imbibes, together with the natural acids and falts, the mineral and metallick particles, with which the different strata are impregnated ; and meeting, in those fiffures, matters which have nearer affinities with the acid, of course difengages it, in whole or in part, from the metallick and mineral particles, which it had held diffolved; and which, on being fo difengaged, by the natural attraction between its parts, forms different ores, more or lefs homogeneous, and more or lefs rich, according to the different mixtures, which the acid had held diffolved, and the nidus in which it is depofited. The acid, now impregnated with a new matter, paffes on; till meeting with fome other convenient nidus, it lodges in that, and thereby acquires a fresh impregnation, perhaps at last totally unmetallick; or, for want of meeting with a proper nidus, appears at the furface, weakly or strongly tinctured with those principles it had last imbibed.

By means of these acids, the Miners are often put to an extraordinary expence for Brafs pumps inftead of Iron; for many of the Mines have water fo fully imbued with acid, that the Iron working-pieces, in which the piston of the pump works, will be entirely corroded therewith in fix months; and a great expence and lofs of time will be incurred, if the pumps are not previously furnished with Brass working pieces, as on them the acids, which are already faturated with kindred particles, have little effect.

Thefe, I prefume, are plain demonftrations: whence it appears, that Goffan, which is an ochreous Stone, ruddy, and crumbling like the ruft of Iron, much of which it really contains, is a proper nidus for moft kinds of Metals and Minerals; Iron having, even in this its mineral state, so ftrong an affinity with the acids, as to decompofe them, when faturated with other Metals, Semi-metals, &c. on which decompofition, the precipitated matters become Ores of different kinds, and even virgin Metals, as before defcribed.

In