The principle and most gemmary affection is its Tralucency: as for irradiancy or sparkling which is found in many gemms, it is not discoverable in this, for it cometh short of their compactness and durity: and therefore requireth not the Emery, as the Saphir, Granate, and Topaz, but will receive impression from Steel, in a manner like the Turchois. As for its diaphanity or perspicuity, it enjoyeth that most eminently; and the reason thereof is its continuity; as having its earthy and salinous parts so exactly resolved, that its body is left imporous and not discreted by atomical terminations. For, that continuity of parts is the cause of perspicuity, it is made perspicuous by two ways of experiment. That is, either in effecting transparency in those bodies which were not so before, or at least far short of the additional degree: So Snow becomes transparent upon liquation, so Horns and Bodies resolvable into continued parts or gelly. The like is observable in oyled paper, wherein the interstitial divisions being continuated by the accession of oyl, it becometh more transparent, and admits the visible rayes with less umbrosity. Or else the same is effected by rendring those bodies opacous, which were before pellucid and perspicuous.
So Glass which was before diaphanous, being by powder reduced into multiplicity of superficies, becomes an opacous body, and will not transmit the light. So it is in Crystal powdered, and so it is also before; for if it be made hot in a crucible, and presently projected upon water, it will grow dim, and abate its diaphanity; for the water entering the body, begets a division of parts, and a termination of Atoms united before unto continuity.
The ground of this Opinion might be, first the conclusions of some men from experience; for as much as Crystal is found sometimes in rocks, and in some places not much unlike the stirious or stillicidious dependencies of Ice. Which notwithstanding may happen either in places which have been forsaken or left bare by the earth, or may be petrifications, or Mineral indurations, like other gemms, proceeding from percolations of the earth disposed unto such concretions.
The second and most common ground is from the name Crystallus, whereby in Greek both Ice and Crystal are expressed; which many not duly considering, have from their community of name, conceived a community of nature; and what was ascribed unto the one, not unfitly appliable unto the other. But this is a fallacy of Æquivocation, from a society in name inferring an Identity in nature. By this fallacy was he deceived that drank Aqua fortis for strong water. By this are they deluded, who conceive sperma Cœti which is found about the head, to be the spawn of the Whale: Or take sanguis draconis (which is the gumme of a tree,) to be the blood of a Dragon. By the same Logick we may infer, the Crystalline humour of the eye, or rather the Crystalline heaven above, to be of the substance of Crystal here below; Or that God sendeth down Crystal, because it is delivered in the vulgar translation, Psal. 47. Mittit Crystallum suum sicut Buccellas. Agreement in name. Which translation although it literally express the Septuagint; yet is there no more meant thereby, than what our translation in plain English expresseth; that is, he casteth forth his Ice like morsels, or what Tremellius and Junius as clearly deliver, Deficit gelu suum sicut frusta, coram frigore ejus quis consistet? which proper and latine expressions, had they been observed in ancient translations, elder Expositors had not been misguided by the Synonomy; nor had they afforded occasion unto Austin, the Gloss, Lyranus, and many others, to have taken up the common conceit, and spoke of this Text conformably unto the opinion rejected.
[CHAPTER II]
Concerning the Loadstone.
Of things particularly spoken thereof, evidently or probably true. Of things generally believed, or particularly delivered, manifestly or probably false. In the first of the Magnetical vertue of the Earth, of the four motions of the stone, that is, its Verticity or Direction, its Attraction or Coition, its Declination, its Variation, and also of its Antiquity. In the second a rejection of sundry opinions and relations thereof, Natural, Medical, Historical, Magical.
How the earth is a Magnetical body.
And first we conceive the earth to be a Magnetical body. A Magnetical body, we term not onely that which hath a power attractive, but that which seated in a convenient medium, naturally disposeth it self to one invariable and fixed situation. And such a Magnetical vertue we conceive to be in the Globe of the Earth, whereby as unto its natural points and proper terms, it disposeth it self unto the poles; being so framed, constituted, and ordered unto these points, that those parts which are now at the poles, would not naturally abide under the Æquator, nor Greenland remain in the place of Magellanica. And if the whole earth were violently removed, yet would it not foregoe its primitive points, nor pitch in the East or West, but return unto its polary position again. For though by compactness or gravity it may acquire the lowest place, and become the center of the universe, yet that it makes good that point, not varying at all by the accession of bodies upon, or secession thereof from its surface, perturbing the equilibration of either Hemisphere (whereby the altitude of the stars might vary) or that it strictly maintains the North and Southern points; that neither upon the motions of the heavens, air, and winds without, large eruptions and division of parts within, its polary parts should never incline or veer unto the Equator (whereby the latitude of places should also vary) it cannot so well be salved from gravity as a Magnetical verticity. The foundation of the Earths stability. This is probably, that foundation the wisdom of the Creator hath laid unto the earth; in this sense we may more nearly apprehend, and sensibly make out the expressions of holy Scripture Psal. 93., as Firmavit orbem terræ qui non commovebitur, he hath made the round world so sure that it cannot be moved: as when it is said by Job, Extendit Aquilonem super vacuo, &c. Job 38. He stretcheth forth the North upon the empty place, and hangeth the earth upon nothing. And this is the most probable answer unto that great question. Whereupon are the foundations of the Earth fastened, or who laid the corner stone thereof? Had they been acquainted with this principle, Anaxagoras, Socrates, and Democritus, had better made out the ground of this stability; Xenophanes had not been fain to say the Earth had no bottom; and Thales Milesius to make it swim in water.