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?