the condition and action of the particles of the insulating dielectric itself (1337.).  If the globe were charged, these little conductors would all be polar; if the globe were discharged, they would all return to their normal state, to be polarized again upon the recharging of the globe.  The state developed by induction through such particles on a mass of conducting mutter at a distance would be of the contrary kind, and exactly equal in amount to the force in the inductric globe.  There would be a lateral diffusion of force (1224. 1297.), because each polarized sphere would be in an active or tense relation to all those contiguous to it, just as one magnet can affect two or more magnetic needles near it, and these again a still greater number beyond them.  Hence would result the production of curved lines of inductive force if the inducteous body in such a mixed dielectric were an uninsulated metallic ball (1219. &c.) or other properly shaped mass.  Such curved lines are the consequences of the two electric forces arranged as I have assumed them to be:  and, that the inductive force can be directed in such curved lines is the strongest proof of the presence of the two powers and the polar condition of the dielectric particles.

1680.  I think it is evident, that in the case stated, action at a distance can only result through an action of the contiguous conducting particles.  There is no reason why the inductive body should polarize or affect distant conductors and leave those near it, namely the particles of the dielectric, unaffected:  and everything in the form of fact and experiment with conducting masses or particles of a sensible size contradicts such a supposition.

1681.  A striking character of the electric power is that it is limited and exclusive, and that the two forces being always present are exactly equal in amount.  The forces are related in one of two ways, either as in the natural normal condition of an uncharged insulated conductor; or as in the charged state, the latter being a case of induction.

1682.  Cases of induction are easily arranged so that the two forces being limited in their direction shall present no phenomena or indications external to the apparatus employed, Thus, if a Leyden jar, having its external coating a little higher than the internal, be charged and then its charging ball and rod removed, such jar will present no electrical appearances so long as its outside is uninsulated.  The two forces which may be said to be in the coatings, or in the particles of the dielectric contiguous to them, are entirely engaged to each other by induction through the glass; and a carrier ball (1181.) applied either to the inside or outside of the jar will show no signs of electricity.  But if the jar be insulated, and the charging ball and rod, in an uncharged state and suspended by an insulating thread of white silk, be restored to their place, then the part projecting above the jar will give electrical indications and charge the carrier, and at the same time the outside coating of the jar will be found in the opposite state and inductric towards external surrounding objects.