done them, as Ambrose, Austine, Gulielmus Parisiensis, and many more; but these fall under no rule, and are as boundless as men's inventions. And, though honest minds do glorify God hereby, yet do they most powerfully magnify him, and are to be looked on with another eye, who demonstratively set forth its magnalities; who not from postulated or precarious inferences entreat a courteous assent, but from experiments and undeniable effects enforce the wonder of its maker.

CHAPTER IV.

Of Bodies Electrical.

HAVING thus spoken of the loadstone and bodies magnetical, I shall, in the next place, deliver somewhat of electrical, and such as may seem to have attraction like the other. Hereof we shall also deliver what particularly spoken or not generally known is manifestly or probably true, what generally believed is also false or dubious. Now, by electrical bodies I understand, not such as are metallical, mentioned by Pliny and the ancients, for their electrum was a mixture made of gold, with the addition of a fifth part of silver-a substance now as unknown as true aurichalcum, or Corinthian brass, and set down among things lost by Pancirollus; nor by electric bodies do I conceive such only as take up shavings, straws, and light bodies (in which number the ancients only placed jet and amber); but such as, conveniently placed unto their objects, attract all bodies palpable whatsoever. I say conveniently placed, that is, in regard of the object, that it be not too ponderous, or any way affixed: in regard of the agent, that it be not foul or sullied, but wiped, rubbed, and excitated; in regard of both, that they be conveniently distant, and no impediment interposed. I say, all bodies palpable, thereby excluding fire, which indeed it will not attract, nor yet draw through it; for fire consumes its effluxions by which it should attract.

Now, although in this rank but two were commonly mentioned by the ancients, Gilbertus discovereth many more; as diamonds, sapphires, carbuncles, iris, opals, amethysts, beryl, crystal, Bristol stones, sulphur, mastic, hard wax, hard resin,

arsenic, sal-gemma, roche alum, common glass, stibium, or glass of antimony, Unto these, Cabeus addeth white wax, gum elemi, gum guaiaci, pix hispanica, and gypsum. And unto these we add gum animi, benjamin talcum, china-dishes, sandaraca, turpentine, styrax liquida, and caranna dried into a hard consistence.6 And the same attraction we find not only in simple bodies, but such as are much compounded: as in the oxycroceum plaster, and obscurely that ad herniam and gratia Dei; all which, smooth and rightly prepared, will discover a sufficient power to stir the needle, settled freely upon a well pointed pin; and so as the electric may be applied unto it without all disadvantage.

But the attraction of these electrics we observe to be very different. Resinous or unctuous bodies, and such as will flame, attract most vigorously, and most thereof without frication; as animi, benjamin, and most powerfully good hard wax, which will convert the needle almost as actively as the loadstone. And we believe that all, or most of this substance, if reduced to hardness, tralucency, or clearness, would have some attractive quality. But juices concrete, or gums easily dissolving in water, draw not at all; as aloe, opium, sanguis draconis, lacca, galbanum, sagapenum. Many stones also, both precious and vulgar, although terse and smooth, have not this power attractive: as emeralds, pearl, jaspis, cornelians, agate, heliotropes, marble, alabaster, touchstone, flint, and bezoar. Glass attracts but weakly, though clear; some slick stones, and thick glasses indifferently; arsenic but weakly; so likewise glass of antimony; but crocus metallorum not at all. Salts generally, but weakly; as sal gemma, alum, and also tale; not very discoverably by any frication; but, if gently warmed at the fire, and wiped with a dry cloth, they will better discover their electricities.

6 And unto these we add gum animi, &c.] The author is perfectly correct in adding (evidently from his own experiments) these substances to the list of electrics. The "compounded bodies," which he next mentions, derive their electrical properties chiefly from the resin or wax which they contain.-Br.

7 slick.] Smooth.

8 crocus metallorum.] And yet (which is the more to be enquired) crocus martis, which hath much affinitye to, and his first original from iron, should in common reason attract more than any of the other.-Wr.

No metal attracts, nor animal concretion we know, although polite and smooth; as we have made trial in elk's hoofs, hawks' talons, the sword of a sword-fish, tortoiseshells, sea-horse, and elephants' teeth, in bones, in hart's horn, and what is usually conceived unicorn's horn. No wood, though never so hard and polished, although out of some thereof electric bodies proceed; as ebony, box, lignum vite, cedar, &c. And, although jet and amber be reckoned among bitumens, yet neither do we find asphaltum, that is, bitumen of Judea, nor sea-coal, nor camphor, nor mummia, to attract, although we have tried in large and polished pieces. Now this attraction have we tried in straws and paleous bodies, in needles of iron equilibrated, powders of wood and iron, in gold and silver foliate; and not only in solid, but fluent and liquid bodies, as oils made both by expression and distillation, in water, in spirits of wine, vitriol, and aqua fortis.

But how this attraction is made, is not so easily determined: that it is performed by effluviums is plain, and granted by most; for electrics will not commonly attract, except they grow hot, or become perspirable. For if they be foul and obnubilated, it hinders their effluxion; nor if they be covered, though but with linen or sarsenet, or if a body be interposed, for that intercepts the effluvium. If also a powerful and broad electric of wax or animi be held over fine powder, the atoms or small particles will ascend most numerously unto it; and if the electric be held unto the light, it may be observed that many thereof will fly, and be as it were discharged from the electric,1 to the distance

9 No metal attracts, nor animal concretion we know.] Browne is in error respecting all the substances which he mentions in this paragraph, as well as in preceding and following ones, as not susceptible of electrical excitation; for all of them are in fact electrics. But as many among the number, especially the metals, require very perfect insulation, before they can be made to manifest electricity by friction, as many others, especially the true gums, the animal concretions, and the woods, require also to be made very dry; and as some further precautions are necessary in certain cases, in order to insure the success of the experiment, our author's failure, and consequent errors on this subject, are readily explained.-Br.

be as it were discharged from the electric.] The true cause of this projection of the atoms," is to be found in the law of electrical attraction and repulsion: bodies similarly electrified, repel, and dissimilarly electri

sometimes of two or three inches. Which motion is performed by the breath of the effluvium issuing with agility; for as the electric cooleth, the projection of the atoms ceaseth.

The manner hereof Cabeus wittily attempteth, affirming that this effluvium attenuateth and impelleth the neighbour air, which returning home in a gyration, carrieth with it the obvious bodies unto the electric. And this he labours to confirm by experiments; for if the straws be raised by a vigorous electric, they do appear to wave and turn in their ascents. If, likewise, the electric be broad, and the straws light and chaffy, and held at a reasonable distance, they will not arise unto the middle, but rather adhere toward the verge or borders thereof. And, lastly, if many straws be laid together, and a nimble electric approach, they will not all arise unto it, but some will commonly start aside, and be whirled a reasonable distance from it. Now, that the air impelled returns unto its place in a gyration or whirling, is evident from the atoms or moats in the sun. For when the sun so enters a hole or window, that by its illumination the atoms or motes become perceptible, if then by our breath the air be gently impelled, it may be perceived that they will circularly return, and in a gyration,2 unto their places again.

Another way of their attraction is also delivered; that is, by a tenuious emanation or continued effluvium, which after some distance retracteth into itself; as is observable in drops of syrups, oil, and seminal viscosities, which spun at length, retire into their former dimensions. Now these effluviums advancing from the body of the electric, in their return do carry back the bodies, whereon they have laid hold, within the sphere or circle of their continuities; and these they do not only attract, but with their viscous arms hold fast a good while after. And if any shall wonder why these effluviums issuing forth impel and protrude not the straw before they

fied, attract each other. The particles are first attracted by the excited electric, because they are in a dissimilar state of electricity to it; by contact with it, however, they acquire a similar state of electricity, and are, in consequence repelled from it.—Br.

2

gyration.] The same gyration appeares in thistledowne, and small feathers, and the smoke of a snuff, &c.-Wr.

can bring it back; it is because the effluvium, passing out in a smaller thread and more enlengthened filament, stirreth not the bodies interposed, but, returning unto its original, falls into a closer substance and carrieth them back unto itself. And this way of attraction is best received, embraced by Sir Kenelm Digby in his excellent treatise of bodies, allowed by Des Cartes in his Principles of Philosophy, as far as concerneth fat and resinous bodies, and with the exception of glass, whose attraction he also deriveth from the recess of its effluxion. And this in some manner the words of Gilbertus will bear. Effluvia illa tenuiora concipiunt et amplectuntur corpora, quibus uniuntur, et electris tanquam extensis brachiis, et ad fontem propinquitate invalescentibus effluviis, deducuntur. And if the ground were true, that the earth were an electric body, and the air but the effluvium thereof, we might have more reason to believe that from this attraction, and by this effluxion, bodies tended to the earth, and could not remain above it.3

Our other discourse of electricks concerneth a general opinion touching jet and amber, that they attract all light bodies, except ocymum or basil, and such as be dipped in oil or oiled; and this is urged as high as Theophrastus. But Scaliger acquitteth him; and had this been his assertion, Pliny would probably have taken it up, who herein stands out, and delivereth no more but what is vulgarly known. But Plutarch speaks positively in his Symposiacks, that amber attracteth all bodies, excepting basil and oiled substances. With Plutarch consent many authors, both ancient and modern; but the most inexcusable are Lemnius and Rueus : whereof the one, delivering the nature of minerals mentioned in Scripture, the infallible fountain of truth, confirmeth their virtues with erroneous traditions; the other, undertaking the occult and hidden miracles of nature, accepteth this for

3 And if the ground, &c.] That there is a constant breathing of the earth every twelve houres, where itt may easily break forthe, as in the botome of the ocean, is more than probable by the rising of the seas every twelve houres, which wee call the flow, which when it is lifted up by the volubility of its nature, is apt to follow the leading of the moone, but is not raised by itt, because itt keeps a constant course, if there be no strong impediment, as well when she is under, as when above the earthe.-Wr.