Page:Aether and Matter, 1900.djvu/12

vi rapidly the times became ripe for the quantitative electro-chemcial investigations of his successor Faraday. Since Faraday's work on electrolysis the notion of the atomic constitution of electrification, in its electro-chemical aspect, has never been entirely absent: it has been insisted on by Maxwell and more particularly by von Helmholtz: it was adapted, in the most natural manner, to the ideas of the Weberian electrodynamics, which treated of moving electric particles: but it is only recently that any efforts have been made towards the development of the Maxwellian aether-theory on that basis.

The form under which the atomic electric theory is introduced in this Essay, originally presented itself - as it happened - in a quite different connexion, in the course of an inquiry into the competence of the aether devised by Mac Cullagh to serve for electrical purposes as well as optical ones. It was found, reasoning entirely from abstract principles, that the only possible way of representing electrification, in an elastic aether, was as a system of discrete or isolated electric charges, constituting singular points involving intrinsic strain in the structure of the medium. If the propagation of disturbances in the aether, with their ascertained optical properties, is to be explained dynamically at all, that is by the interaction of inertia and motion, the elastic reaction of this medium to displacement is almost restricted, as Mac Cullagh showed, to be effectively (even if not fundamentally ) a purely rotational one; an essential confirmation of this rotational character of its elasticity here presents itself in the fact that in a medium