And therefore, this may serve as a trial of good steel,4 the loadstone taking up a greater mass of that which is most pure. It may also decide the conversion of wood into iron, as is pretended, from some waters; and the common conversion of iron into copper, by the mediation of blue copperas; for the loadstone will not attract it. Although it may be questioned, whether, in this operation, the iron or copperas be transmuted,5 as may be doubted from the cognation of copperas with copper, and the quantity of iron remaining after the conversion. And the same may be useful

4 as a trial of good steel.] This statement is no further true than that the magnet, if caused to act upon filings of iron or steel in which the metal fully retained its metallic form, free from oxidation, and also upon similar filings which had become partially oxidated, would attract a greater quantity of the former than of the latter. As a trial of the purity or goodness of iron or steel in the mass, the proposed test is quite nugatory.--Br.

5 whether in this operation the iron or copperas be transmuted.] This alleged conversion of iron into copper is an experiment of the alchymists and of the old chemists their successors; the true nature of which has been explained by modern chemists, and appears, from the passage before us, to have been suspected also by Browne. The metallic salt, here termed "blue copperas " (or blue vitriol, as it is also called), is properly a hydrated persulphate of copper, a combination of the peroxide of that metal with the sulphuric acid and with water. But iron, having a stronger chemical attraction for oxygen than copper has, when immersed in a solution of this salt, attracts and unites with the oxygen of a part of the peroxide of copper, thus separating an equivalent quantity of the copper itself, which being precipitated, in its pure metallic state, upon the iron, imparts to it externally the appearance of copper, just as gilding would impart that of gold. It was formerly imagined, however (and the experiment was cited as demonstrating the transmutability of metals into one another), that part of the iron was actually converted into copper. But our author, knowing the cognation of [blue] copperas with copper," and considering "the quantity of iron remaining after the conversion," justly questions whether the iron or the " copperas" "be transmuted." It is evident from this, that he entertained as correct a notion upon the subject as it was possible to arrive at in the existing state of chemical knowledge; for, although in reality a particle of iron becomes dissolved in the solution for every particle of copper which is precipitated from it, yet, in the manner in which the experiment is commonly made, and as it was always made formerly, the iron is not sensibly diminished in substance, and continues unaltered in form, so that the obvious essential change takes place with the metallic salt only. The last sentence of the first period alluding to this subject would be more readily intelligible, were it read "for the loadstone will not attract the copperas.”—Br.

to some discovery concerning vitriol or copperas of Mars, by some called salt of steel, made by the spirits of vitriol or sulphur. For the corroded powder of steel will, after ablution, be actively attracted by the loadstone, and also remaineth in little diminished quantity; and therefore, whether those shooting salts partake but little of steel, and be not rather the vitriolous spirits fixed into salt by the effluvium or odour of steel, is not without good question.?

CHAPTER III.

Concerning the Loadstone; a rejection of sundry common opinions and relations thereof; natural, medical, historical, magical.

AND first, not only a simple heterodox, but a very hard paradox, it will seem, and of great absurdity unto obstinate ears, if we say, attraction is unjustly appropriated unto the loadstone, and that perhaps we speak not properly, when we say vulgarly and appropriately, the loadstone draweth iron; and yet herein we should not want experiment and great authority. The words of Renatus des Cartes, in his Principles of Philosophy, are very plain. Præterea magnes trahit ferrum, sive potiùs magnes et ferrum ad invicem acce

6 some discovery concerning vitriol or copperas of Mars.] The salt here alluded to, commonly termed green vitriol, is the hydrated protosulphate of iron,—a combination of the protoxide of iron with the sulphuric acid and with water, bearing nearly the same relation to metallic iron which blue vitriol bears to metallic copper. The manner in which Browne adverts to these substances, evinces that he entertained approximately correct ideas respecting the nature of the several salts termed copperas. But when he supposes that "those shooting salts" (meaning thereby the hydrated protosulphate of iron), "partake but little" of the metal from which they are formed, he is entirely mistaken. He appears to have been led into this error by the application of his own proposed magnetic test: finding that the "corroded powder of steel," the nature of which is explained in our preceding note, was readily attracted by the magnet, but that the " copperas of Mars was not, he seems to have inferred that that salt could not be materially related to the metal from which it is formed; not knowing that those substances which obey the magnet in their metallic state, and in some instances in their oxidated form also, cease to be amenable to its influence when united with acids into salts.-Br.

7 And therefore, &c.] Added in 2nd edition.

dunt, neque enim ulla ibi tractio est. The same is solemnly determined by Cabeus. Nec magnes trahit propriè ferrum, nec ferrum ad se magnetem provocat; sed ambo pari conatu ad invicem confluunt. Concordant hereto is the assertion of Dr. Ridley, physician to the emperor of Russia, in his tract Of Magnetical Bodies, defining magnetical attraction to be a natural incitation and disposition conforming unto contiguity, an union of one magnetical body with another, and no violent haling of the weak unto the stronger. And this is also the doctrine of Gilbertus, by whom this motion is termed coition, and that not made by any faculty attractive of one, but a syndrome and concourse of each,1 a coition always of their vigours, and also of their bodies, if bulk or impediment prevent not. And therefore, those contrary actions, which flow from opposite poles or faces, are not so properly expulsion and attraction, as sequela and fuga, a mutual flight and following. Consonant whereto are also the determinations of Helmontius, Kircherus, and Licetus.2

The same is also confirmed by experiment; for if a piece of iron be fastened in the side of a bowl or basin of water, a loadstone, swimming freely in a boat of cork, will presently make unto it. So if a steel or knife untouched be offered toward the needle that is touched, the needle nimbly moveth. toward it, and conformeth unto a union with the steel that moveth not. Again, if a loadstone be finely filed, the atoms. or dust thereof will adhere unto iron that was never touched, even as the powder of iron doth also unto the loadstone. And, lastly, if in two skiffs of cork, a loadstone and steel be placed within the orb of their activities, the one doth not move, the other standing still, but both hoist sail and steer unto each other. So that if the loadstone attract, the steel hath also its attraction; for in this action the alliciency isreciprocal, which jointly felt, they mutually approach and run into each other's arms.

1 concourse of each.] Ross, on the ground that " no end can be assigned why the loadstone should move towards the iron," denies that they move towards each other; thinking it more reasonable to suppose that iron and other metals move towards the loadstone as to their matrix. -Arcana, p. 191.

2 Consonant, &c.] Added in the 2nd edition.

And therefore, surely, more moderate expressions become this action, than what the ancients have used; which some have delivered in the most violent terms of their language; so Austin calls it, mirabilem ferri raptorem: Hippocrates, Xilos o Tɩ Tòv oídпpov åρráže, lapis qui ferrum rapit. Galen, disputing against Epicurus, useth the term Aker, but this also is too violent; among the ancients, Aristotle spake most warily, Moos oorg Tòv σidпpov kivet, lapis qui ferrum movet: and in some tolerable exception do run the expressions of Aquinas, Scaliger, and Cusanus.

Many relations are made, and great expectations are raised from the magnes carneus, or a loadstone that hath a faculty to attract not only iron, but flesh; but this, upon enquiry, and as Cabeus hath also observed, is nothing else but a weak and inanimate kind of loadstone, veined here and there with a few magnetical and ferreous lines, but chiefly consisting of a bolary and clammy substance, whereby it adheres like hamatites or terra Lemnia, unto the lips. And this is that stone which is to be understood, when physicians join it with atites, or the eagle-stone, and promise therein a virtue against abortion.

There is sometimes a mistake concerning the variation of the compass, and therein one point is taken for another. For beyond the equator some men account its variation by the diversion of the northern point; whereas beyond that circle, the southern points is sovereign, and the north submits his pre-eminency. For in the southern coast, either of America or Africa, the southern point deflects and varieth toward the land, as being disposed and spirited that way by the meridional and proper hemisphere. And, therefore, on that side of the earth, the varying point is best accounted by the south. And therefore, also, the writings of some, and maps of others, are to be enquired, that make the needle decline unto the east twelve degrees at Capo Frio, and six at the straits of Magellan; accounting hereby one point for

3 beyond that circle, &c.] The author was here much mistaken: the southern pointe having noe soveranty at all-noe not in the southern olymats, as our navigators unanimously affirme.—Wr.

The dean's contradiction must be flatly thrown back upon him. The fact is found to bear out our author's assertion, which is correct both as to substance and literality.

another, and preferring the north in the liberties and province of the south.4

But certainly false it is, what is commonly affirmed and believed, that garlick doth hinder the attraction of the loadstone5 which is, notwithstanding, delivered by grave and worthy writers, by Pliny, Solinus, Ptolemy, Plutarch, Albertus, Matthiolus, Rueus, Langius, and many more. An effect as strange as that of Homer's Moly, and the garlick that Mercury bestowed upon Ulysses. But that it is evidently false, many experiments declare. For an iron wire heated red hot and quenched in the juice of garlick, doth, notwithstanding, contract a verticity from the earth, and attracteth the southern point of the needle. If, also, the tooth of a loadstone be covered or stuck in garlick, it will, notwithstanding, attract; and needles, excited and fixed in garlick, until they begin to rust, do yet retain their attractive and polary respects.

Of the same stamp is that which is obtruded upon us by authors ancient and modern, that an adamant or diamond prevents or suspends the attraction of the loadstone; as is in open terms delivered by Pliny: Adamas dissidet cum magnete lapide, ut juxtà positus ferrum non patiatur abstrahi, aut si admotus magnes apprehenderit, rapiat atque auferit. For if a diamond be placed between a needle and a loadstone, there will, nevertheless, ensue a coition even over the body of the diamond. And an easy matter it is to touch or excite a needle through a diamond, by placing it at the tooth of a loadstone: and, therefore, the relation is false; or our estimation of these gems untrue, nor are they diamonds which carry that name amongst us.

4 and preferring, &c.] Itt is certaine that the needle holds the same posture to the northe, and moves to iron on the south side the line, in the self-same manner as itt did being toucht in England, and that the south pointe of the needle does [there] fly from iron as itt does here.- Wr.

5 garlick doth hinder, &c.] Nothing can afford a more perfect example of implicit adherence to antiquity, than the following passage from Ross:"I cannot think the ancient sages would write so confidently of that which they had no experience of, being a thing so obvious and easy to try; therefore I suppose they had a stronger kind of garlick than is with us!"-Arcana, p. 192.

6 and therefore the relation, &c.] The paragraph containing this result, the preceding, and the two following ones, all furnish examples