39. A quiescent charge of frictional electricity, only affecting the superficies of any ponderable mass with which it may be associated, and having no influence upon the component ethereo-ponderable atoms severally, is not to be ascribed to redundancies or deficiencies of the ethereal matter, but to different states of polarization produced in different sets of the particles of such matter existing about the electrifiable bodies.[66] During the action of an electrical machine, these particles are polarized by the opposite polarities transiently induced in the surfaces subjected to friction; one set of particles going with the electric, the other remaining with the rubber.
40. The particles thus oppositely polarized, severally divide their appropriate polarities with other ethereal matter surrounding the conductors, and this, when insulated, is retained until a further polarization results from the same process. Thus are the ethereo-electric atmospheres respectively surrounding the positive and negative conductors oppositely polarized, and consequently charged to the degree which the machine is competent to induce. Under these circumstances, if a conducting rod be made to form between them a communication, by touching each conductor with one of its ends, the polarities of the ethereo-electric atmospheres by which they are severally surrounded propagate themselves, by a wave-like process, over and more or less through the rod, according to its nature and dimensions, so as to meet intermediately, and thus produce reciprocal neutralization.
41. When the oppositely polarizing waves, generated by friction, as above described, are by means of a conducting communication transmitted to the surface of a coated pane, the two different portions of the electro-ether there existing are severally polarized in opposite ways, one being endowed with the properties usually called vitreous, or positive, the other with those usually called resinous, or negative. In fact, the two polarized atmospheres thus created, may be conveniently designated as the “two electricities,” and alluded to in the language heretofore employed in treating of phenomena, agreeably to the hypothesis which assumes the existence of heterogeneous fluids instead of heterogeneous polarities.
42. Of course it will follow, that the oppositely polarized ethereal atmospheres thus produced, one on each surface of the electric which keeps them apart, must exercise toward each other an attraction perfectly analogous to that which has been supposed to be exercised by the imaginary heterogeneous electric fluids of Dufay. The electro-ether[67] being elastic, a condensation over each of the charged surfaces, proportionable to the attractive force must ensue; while over the surface of an electrified conductor, the similarly polarized atoms, not being attracted by those in an oppositely polarized atmosphere beneath the surface, tend, by their reciprocally repulsive reagency, to exist further apart than in a neutral state. Hence, the electro-ether, as it exists over the surface of an insulated conductor, is rendered rarer, while, as existing over the surfaces of charged panes or Leyden jars, it must be in a state of condensation.[68] And, consequently, while the space perceptibly electrified by the charge of a conductor, for equal areas and charging power, is much more extensive than the space in which the charge of a coated pane is perceptible, the striking distance being likewise much greater; yet upon any body, successively subjected to a discharge from each, the effect will be more potent when produced by means of the pane.
Ignition, Electrolysis, and Magnetism, Secondary Effects of Frictional Discharges; or, in other words, of Polarizing Electro-ethereal Waves.
43. In proportion as a wire is small in comparison with the charge which it may be made the means of neutralizing, the conducting power seems to be more dependent on the sectional area,[69] and less upon the extent of surface. The reciprocal repulsion of the similarly polarized ethereal particles must tend always to make them seek the surface, but at the same time their attraction for the ethereo-ponderable particles composing the wire has the opposite effect, and tends to derange these from their normal polar state of quiescence. Commensurate with the extent in which this state is subverted, is the resulting heat, electrolytic power, and electro-magnetic influence. The phenomena last mentioned are, however, secondary effects consequent to the participation of the ethereo-ponderable matter in the undulations resulting from the statical discharge.
44. Such effects, making allowance for the extreme minuteness of the time occupied by the process, are probably, in all cases, proportional to the degree in which the ponderable matter is effected, up to the point at which it is dissipated by deflagration; but the duration of a statical discharge being almost infinitely minute for any length of coil which can conveniently be subjected thereto, the electro-magnetic and other effects of a statical discharge are not commensurate with the intensity of the affection of the wire.
45. There is, in fact, this additional reason for the diversity between the electro-magnetic power of a statical discharge, as compared with that of the voltaic series: any wire which is of sufficient length and tenuity to display the maximum power of deflagration by the former, cannot serve for the same purpose in the case of the latter. Moreover, the form of a helix closely wound, so that the coatings may touch, which is that most favourable for the reiteration of the magnetic influence of the circuit upon an iron rod, cannot be adopted in the case of statical discharges of high intensity, since the proximity of the circumvolutions would enable the ethereal waves, notwithstanding the interposition of cotton or silk, to cross superficially from one to the other, parallel to the axis of the included iron, instead of pursuing the circuitous channel afforded by the helix with the intensity requisite to the polarization of the ponderable atoms.