EXPERIMENT I.
Pass an excited glass tube near the other end of the prime conductor, so as to give it some sparks, and the threads will diverge.
Because each thread, as well as the prime conductor, has acquired an electric atmosphere, which repels and is repelled by the atmospheres of the other threads: if those several atmospheres would readily mix, the threads might unite, and hang in the middle of one atmosphere, common to them all.
Rub the tube afresh, and approach the prime conductor therewith, crossways, near that end, but not nigh enough to give sparks; and the threads will diverge a little more.
Because the atmosphere of the prime conductor is pressed by the atmosphere of the excited tube, and driven towards the end where the threads are, by which each thread acquires more atmosphere.
Withdraw the tube, and they will close as much.
They close as much, and no more; because the atmosphere of the glass tube not having mixed with the atmosphere of the prime conductor, is withdrawn intire, having made no addition to, or diminution from it.
Bring the excited tube under the tuft of threads, and they will close a little.
They close, because the atmosphere of the glass tube repels their atmospheres, and drives part of them back on the prime conductor.
Withdraw it, and they will diverge as much.