The sealing-wax so treated is electrified negatively or resinously, and the glass with positive or vitreous electricity.
Besides their ordinary condition all bodies are capable of being thrown into a physical state in which they are said to be electrified or charged with electricity.
Gilbert employed it to prove that numerous other bodies besides amber are susceptible of being electrified by friction.
Diamond differs from graphite in being a bad conductor of electricity: it becomes positively electrified by friction.
If the plate P is electrified it attracts the strip which stretches out towards it.
Again, if, whilst holding the electrified ebonite over the tray, we touch the latter for a moment and then withdraw the ebonite sheet, the tray will be found to be positively electrified.
In the same manner, if an electrified body carries a positive charge Q electrostatic units and is placed in an electric field at a place where the electric force or electromotive intensity has a value E units, it is urged in the direction of the electric force with a mechanical force equal to QE dynes.
The subject of pyro-electricity, or the power possessed by some minerals of becoming electrified when merely heated, and of exhibiting positive and negative electricity, now began to attract notice.
The second effect is readily attributed to the mutual repulsion of the electrified drops, but the action of feeble electricity in producing apparent coherence was long unexplained.
Instead of rebounding after collision, as the unelectrified drops of clean water generally, or always, do, the electrified drops coalesce, and then the jet is no longer scattered about.