CHAPTER IV

Of Bodies Electrical.

[Sidenote: Bodies Electrical, what?]

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 Electrick 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_, _Saphyrs_, _Carbuncles_, _Iris_, _Opalls_, _Amethysts_, _Beril_, _Crystal_, _Bristol-stones_, _Sulphur_, _Mastick_, hard _Wax_, hard _Rosin_, _Arsenic_, _Sal-gemm_, _Roch-Allum_, common Glass, _Stibium_, or Glass of _Antimony_. Unto these Cabeus addeth white Wax, _Gum Elemi_, _Gum Guaici_, _Pix Hispanica_, and _Gipsum_. And unto these we add _Gum Anime_, _Benjamin_, _Talcum_, _China-dishes_, _Sandaraca_, _Turpentine_, _Styrax Liquida_, and _Caranna_ dried into a hard consistence. And the same attraction we find, not onely in simple bodies, but such as are much compounded; as in the _Oxycroceum_ plaister, and obscurely that _ad Herniam_, and _Gratia Dei_; all which smooth and rightly prepared, will discover a sufficient power to stir the Needle, setled freely upon a well-pointed pin; and so as the Electrick may be applied unto it without all disadvantage.

But the attraction of these Electricks we observe to be very different. Resinous or unctuous bodies, and such as will flame, attract most vigorously, and most thereof without frication; as _Anime_, _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_, _Calbanum_, _Sagapenum_. Many stones also both precious and vulgar, although terse and smooth, have not this power attractive: as _Emeralds_, _Pearl_, _Jaspis_, _Corneleans_, _Agathe_, _Heliotropes_, _Marble_, _Alablaster_, _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_, _Allum_, and also _Talke_; nor very discoverably by any frication, but if gently warmed at the fire, and wiped with a dry cloth, they will better discover their Electricities.

No Metal attracts, nor Animal concretion we know, although polite and smooth; as we have made trial in _Elks_ Hoofs, Hawks-Talons, the Sword of a _Sword-fish_, _Tortois-shells_, _Sea-horse_, and _Elephants_ Teeth, in Bones, in _Harts-horn_, and what is usually conceived _Unicorns-horn_. No Wood though never so hard and polished, although out of some thereof Electrick bodies proceed; as _Ebony_, _Box_, _Lignum vitæ_, _Cedar_, _etc._ And although _Jet_ and _Amber_ be reckoned among _Bitumens_, yet neither do we find _Asphaltus_, that is, _Bitumens_ of _Judea_, nor _Sea-cole_, nor _Camphire_, 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 oyls made both by expression and distillation; in Water, in spirits of Wine, _Vitriol_ and _Aquafortis_.

But how this attraction is made, is not so easily determined; that 'tis performed by effluviums is plain, and granted by most; for Electricks 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 Electrick of Wax or _Anime_ be held over fine powder, the Atoms or small particles will ascend most numerously unto it; and if the Electrick be held unto the light, it may be observed that many thereof will fly, and be as it were discharged from the Electrick to the distance sometime of two or three inches. Which motion is performed by the breath of the effluvium issuing with agility; for as the Electrick cooleth, the projection of the Atoms ceaseth.

[Sidenote: Cabeus _his way for attraction in bodies Electrick_.]

The manner hereof _Cabeus_ wittily attempteth, affirming that this effluvium attenuateth and impelleth the neighbor air, which returning home in a gyration, carrieth with it the obvious bodies unto the Electrick. And this he labours to confirm by experiments; for if the straws be raised by a vigorous Electrick, they do appear to wave and turn in their ascents. If likewise the Electrick 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 Electrick 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 Motes 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 unto their places again.

[Sidenote: _The way of Sir_ Kenelm Digby.]

Another way of their attraction is also delivered; that is, by a tenuous emanation or continued effluvium, which after some distance retracteth into it self; as is observable in drops of Syrups, Oyl, and seminal Viscosities, which spun at length, retire into their former dimensions. Now these effluviums advancing from the body of the Electrick, 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 onely 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 can bring it back, it is because the effluvium passing out in a smaller thred and more enlengthened filament, it stirreth not the bodies interposed, but returning unto its original, falls into a closer substance, and carrieth them back unto it self. And this way of attraction is best received, embraced by Sir _Kenelm Digby_ in his excellent Treaty of bodies, allowed by _Des Cartes_ in his principles of Philosophy, as far and concerneth fat and resinous bodies, and with exception of Glass, whose attraction he also deriveth from the recess of its effluction. And this in some manner the words of _Gilbertus_ will bear: _Effluvia illa tenuiora concipiunt & amplectuntur corpora, quibus uniuntur, & electris tanquam extensis brachiis, & ad fontem propinquitate invalescentibus effluviis, deducuntur_. And if the ground were true, that the Earth were an Electrick body, and the air but the effluvium thereof, we might have more reason to believe that from this attraction, and by this effluction, bodies tended to the Earth, and could not remain above it.

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 oyl or oyled; 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 oyled 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 vertues with erroneous traditions; the other undertaking the occult and hidden Miracles of Nature, accepteth this for one; and endeavoureth to alledge a reason of that which is more then occult, that is, not existent.

Now herein, omitting the authority of others, as the Doctrine of experiment hath informed us, we first affirm, That _Amber_ attracts not Basil, is wholly repugnant unto truth. For if the leaves thereof or dried stalks be stripped into small straws, they arise unto _Amber_, _Wax_, and other Electries, no otherwise then those of Wheat and Rye: nor is there any peculiar fatness or singular viscosity in that plant that might cause adhesion, and so prevent its ascension. But that _Jet_ and _Amber_ attract not straws oyled, is in part true and false. For if the straws be much wet or drenched in oyl, true it is that _Amber_ draweth them not; for then the oyl makes the straws to adhere unto the part whereon they are placed, so that they cannot rise unto the Attractor; and this is true, not onely if they be soaked in Oyl, but spirits of Wine or Water. But if we speak of Straws or festucous divisions lightly drawn over with oyl, and so that it causeth no adhesion; or if we conceive an Antipathy between Oyl and _Amber_, the Doctrine is not true. For _Amber_ will attract straws thus oyled, it will convert the Needles of Dials made either of Brass or Iron, although they be much oyled; for in these Needles consisting free upon their Center, there can be no adhesion. It will likewise attract Oyl it self, and if it approacheth unto a drop thereof, it becometh conical, and ariseth up unto it, for Oyl taketh not away his attraction, although it be rubbed over it. For if you touch a piece of Wax already excitated with common Oyl, it will notwithstanding attract, though not so vigorously as before. But if you moisten the same with any Chymical Oyl, Water, or spirits of Wine, or only breath upon it, it quite omits its attraction, for either its influencies cannot get through, or will not mingle with those substances.

It is likewise probable the Ancients were mistaken concerning its substance and generation; they conceiving it a vegetable concretion made of the gums of Trees, especially _Pine_ and _Poplar_ falling into the water, and after indurated or hardened, whereunto accordeth the Fable of _Phaetons_ sisters: but surely the concretion is Mineral, according as is delivered by _Boetius_. For either it is found in Mountains and mediterraneous parts; and so it is a fat and unctuous sublimation in the Earth, concreted and fixed by salt and nitrous spirits wherewith it meeteth. Or else, which is most usual, it is collected upon the Sea-shore; and so it is a fat and bituminous juice coagulated by the saltness of the Sea. Now that salt spirits have a power to congeal and coagulate unctuous bodies, is evident in Chymical operations; in the distillations of _Arsenick_, sublimate and _Antimony_; in the mixture of oyl of _Juniper_, with the salt and acide spirit of _Sulphur_, for thereupon ensueth a concretion unto the consistence of _Birdlime_; as also in spirits of salt, or _Aqua fortis_ poured upon oyl of Olive, or more plainly in the Manufacture of Soap. And many bodies will coagulate upon commixture, whose separated natures promise no concretion. Thus upon a solution of _Tin_ by _Aqua fortis_, there will ensue a coagulation, like that of whites of Eggs. [SN: _How the stone is bred in the Kidney or Bladder._] Thus the volatile salt of Urine will coagulate _Aqua vitæ_, or spirits of Wine; and thus perhaps (as _Helmont_ excellently declareth) the stones or calculous concretions in Kidney or Bladder may be produced: the spirits or volatile salt of Urine conjoyning with the _Aqua vitæ_ potentially lying therein; as he illustrateth from the distillation of fermented Urine. From whence ariseth an _Aqua vitæ_ or spirit, which the volatile salt of the same Urine will congeal; and finding an earthy concurrence, strike into a lapideous substance.

[Sidenote: _Of a Bee and a Viper involved in Amber._ Mart. _l._ 4.]

Lastly, We will not omit what _Bellabonus_ upon his own experiment writ from _Dantzich_ unto _Mellichius_, as he hath left recorded in his Chapter, _De succino_, that the bodies of _Flies_, _Pismires_, and the like, which are said oft-times to be included in _Amber_, are not real but representative, as he discovered in several pieces broke for that purpose. If so, the two famous Epigrams hereof in _Martial_ are but Poetical, the _Pismire_ of _Brassavolus_ imaginary, and _Cardans Mousoleum_ for a Flie, a meer phansie. But hereunto we know not how to assent, as having met with some whose reals made good their representments.