The second Thing I proposed to shew is, Why a Tube of Glass, rubb’d smartly in the Hand, so as to become electrical, repels Leaf-Gold, Feathers, and other small Bodies; and when they touch any less electrify’d Body, they shall return back again to the Tube, and so vice versa. Now, if what I have been saying be true, how can this Phænomenon be otherwise? For, if that Piece of Leaf-Gold, &c. be electrify’d by the Touch of the Tube, then it has as full Power given to it as the electrify’d Body had to give to it: And when the Gold, &c. touches any other Body, it imparts to it so much of its electrical Property as it had in itself: And then it may be consider’d in the same State it was in when first electrify’d: And so it will be repeatedly attracted to it, and be repell’d toties quoties.
But it may be asked, What causes these attractive and repulsive Faculties? I answer, The Attraction of fiery Particles one to another: For, if all Nature be agitated by this Fire, all Things have it in the common Proportion, as it was intended they should stand in Nature. And therefore, as I have endeavoured to shew, that Electricity is occasioned by crouding on any thing more of this Fire and Force than naturally belonged to it; and as the Flame of a Candle must of Necessity send out of it at its Point an Overplus (without which there could be no Succession or free Motion in its Flame); so, for the same Reason, the Redundancy of what is crouded on may be consider’d as spending itself at each Extremity, that it may thereby reach itself out to any thing, and invite it to it; as I have shewn the Flame descending down the Smoak of a Candle just blown out to kindle it again, will do.
As therefore there is a trite Proverb, passing universally, that where there is Smoak there must be some Fire, I will endeavour to prove, That no Heat, either from Animals, or from any other Cause, can be produced but from this supposed Fire I have been speaking of. For, now, suppose you see the Flame of a Candle circumscribed and limited in its Shape and Size, which it has according to its Snuff; this Thought may serve to illustrate what I mean by the Capsula, which I have supposed passing over the Surface of every Body when it is electrify’d, and seems to be a lambent Flame, being more or less thick, as from the Apparatus more or less Fire has been collected and rubbed together on it, either from the Friction of a glass Tube, or the Globe: Now, as what I am about to shew, is, why this attractive Faculty is found in this Experiment, I would offer to your Consideration, Whether, when common People see the Flame of a Candle circumscrib’d, they think of any Fire which may proceed further than in the Flame of that Candle? Yet every body, on Recollection, knows, that the Flame will heat Parts at a great Distance to such a Degree, as, at length, to kindle them into a Fire. And tho’, till you touch the Flame, your Finger is not immediately burn’d, yet there are shewn to be Emanations of Fire at a Distance from its burning Quality. So here I beg Leave to consider the same Property in this Fire occasion’d by Electricity. For, till you touch this Capsula of lambent Flame (which is commonly to be met with near a Quarter of to Half an Inch short of the Body to be electrify’d) no Effect is perceiv’d, because you have not enter’d into the Vortex of this Whirlpool of Fire: Yet you may suppose that it sends out an Emanation of its Fire beyond it, as other Flames do; which, when it has first, by its Heat, (which I take to be Part of it) prepared small Things to be electrify’d, then they are more easily lick’d into the whole Power, and so become electrify’d. The Reason therefore, why the Gold, and other light Materials, (which I have supposed to have some of this Fire in them) are attracted, is, the Invitation they receive from the curling Effluvia to a closer Contact: And when it has received as much as the former can give it, its Invitation ceases, till it has parted with what it had to its Neighbour; and then it is again invited as before.
I come now to consider the Violence of this Fire; which, passing thro’ the Pores of the glass Tube, may, as the Sound of Organ-Pipes, which proceeds only from their differently modifying the Air, cause the various hissing Noises you hear when the Tube is held nigh the Ear, from the Electricity passing through the different shaped Pores of it.
And furthermore the Wind may seem to arise, from the distant Parts of the electrical Force playing at some Space from the Tube; which thereby agitate and fan the ambient Air, so as to make it feel like Wind.
The third Thing I proposed to shew, is, Why the electrical Power departs from one Thing to another by giving a smart Crack, and send-out a Spark, which will set on fire many very inflammable Liquors.
Now, (as I have, I hope, demonstrated) when this Fire of Electricity is issuing out at a Point into an inflammable Spirit, it can be no Wonder, that the Spirit, which is known to be full of Fire, should unite its Fire to that of Electricity.
As to the Crack it gives when this Fire passes away: As all Sounds are occasioned only by the Air’s being put into a different Modification, it is here natural to suppose, that as the Cracking of a Whip is caused by the smart Stroke at the Point of it on the Air, so, in this Case, the Air seems to be agitated in the same manner, by breaking the Continuity of it, whereby the like Sound is perceiv’d.
The next Thing I propose to account for, is, Why a Company of unelectrify’d Persons, who are joined together by their holding each a Piece of iron Wire betwixt them, tho’ they are ever so many, do all receive a violent Blow or Concussion on their Bodies, when one of them touches a Piece of electrify’d Iron.—I think this Experiment may be carried so far, that, as it has been found already sufficient to kill Birds, and hurt many Persons very grievously, it may have Force enough given to it to kill a Man, as effectually as the Darting of Lightning can do.
For if you consider, that you may as effectually electrify one Quantity of Iron as another, that it may be done to many Ton Weight as easily as to a small Piece, and that, when it departs into a Person, all the Power given to it, not only on its Surface, but intimately thro’ every Pore and Particle of it, darts like Lightning from the Point only it was touch’d in; then further think, that if this Repercussion, or infinite Recoil, from so large and solid a Body, be so great, when its Power is thus sent, what may it not do in its utmost Extent?