And as the knowledge of its verticity is not so old as some conceive, so it is more ancient then most believe; nor had its discovery with Guns, Printing, or as many think, some years before the discovery of America. For it was not unknown unto Petrus Peregrinus a Frenchman, who two hundred years since left a Tract of the Magnet, and a perpetual motion to be made thereby, preserved by Gasserus. Paulus Venetus, and about five hundred years past Albertus Magnus make mention hereof, and quote for it a Book of Aristotle, De Lapide; which Book although we find in the Catalogue of Laertius, yet with Cabeus we may rather judge it to be the work of some Arabick Writer, not many years before the days of Albertus.
Lastly, It is likewise true what some have delivered of Crocus Martis, that is, Steel corroded with Vinegar, Sulphur, or otherwise, and after reverberated by fire. For the Loadstone will not at all attract it, nor will it adhere, but lye therein like Sand. This to be understood of Crocus Martis well reverberated, and into a violet colour: for common chalybs præparatus, or corroded and powdered Steel, the Loadstone attracts like ordinary filings of Iron; and many times most of that which passeth for Crocus Martis. So that this way may serve as a test of its preparation; after which it becometh a very good medicine in fluxes. The like may be affirmed of flakes of Iron that are rusty and begin to tend unto Earth; for their cognation then expireth, and the Loadstone will not regard them.
And therefore this may serve as a trial of good Steel. 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 blew Coperose, for the Loadstone will not attract it. Although it may be questioned, whether in this operation, the Iron or Coperose be transmuted, as may be doubted from the cognation of Coperose with Copper; and the quantity of Iron remaining after the conversion. And the same may be useful to some discovery concerning Vitriol or Coperose 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 odor of Steel, is not without good question.
[CHAPTER III]
Concerning the Loadstone, therein of sundry common Opinions, and received several relations: Natural, Historical, Medical, 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 trahet ferrum, sive potius magnes & ferrum ad invicem accedunt, neque enim ulla ibi tractio est. The same is solemnly determined by Cabeus. Nec magnes trahit proprie ferrum, nec ferrum ad se magnetem provocat, sed ambo pari conatu ad invicem confluunt. Concordant hereto is the assertion of Doctor Ridley, Physitian unto the Emperour 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; a Coition alway 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 determination of Helmontius, Kircherus, and Licetus.
Attraction reciprocal betwixt the Loadstone and Iron.
The same is also confirmed by experiment; for if a piece of Iron be fastened in the side of a bowl or bason water, a Loadstone swimming freely in a Boot 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 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 hoise sail and steer unto each other. So that if the Loadstone attract, the Steel hath also its attraction; for in this action the Alliciency is reciprocal, which joyntly felt, they mutually approach and run into each others arms.