Page:Proceedings of the Royal Society of London Vol 4.djvu/78

Rh sioned by a momentary and independent action of the same kind. The disruptive discharge may take place at degrees of tension so low as not to give rise to any luminous appearance ; so that a dark space may intervene in the line of actual discharge, as is frequently observable between the brush on one side, and the glow on the other. Thus it is inferred that electric light is merely a consequence of the quantity of electricity which, after a discharge has com- menced, flows and converges towards the spot where it finds the readiest passage : and these conclusions are further confirmed by the phenomena which take place in other gases, besides atmospheric air, and which are specifically detailed by the author.

The last kind of discharge which is here considered is the con- vective or carrying discharge, namely, that effected by the transla- tion of charged particles from one place to another. The phenomena attending this mode of transference are examined under various aspects as they occur in air, in liquids of various kinds, in flame, and as they are exhibited in the case of particles of dust, which perform the office of carriers of the electricity; and also in that of solids terminated by liquids. Thus all these apparently isolated phenomena comprised under the heads of the electric currents which characterize electrolyzation, of transference through dielectrics by disruptive discharges of various kinds, or by the actual motion of charged particles, and of conduction through conductors of various degrees of power, are assimilated to one another by their being shown to be essentially the result of actions of contiguous particles of matter assuming particular states of polarization.

The author lastly considers electric currents, not only in their effects on the bodies they traverse, but also in their collateral in- fluences as producing inductive and magnetic phenomena. The analogies, which connect electrolytic discharge w^ith that by con- duction, are pointed out, as tending to show that they are essentially the same in kind, and that when producing difi'erent kinds of mo- tion in the particles of matter, their mode of operation may be re- garded as identical. An attempt is made to connect with these views the lateral or transverse actions of currents, which are most distinctly manifested in their magnetic effects ; these eff'ects being produced equally by the disruptive, the conductive, and the electro- lytic discharges, and probably depending on the transverse condition of the lines of ordinary induction. This transverse power has the character of polarity impressed upon it, and, in its simplest form, appears as attractive or repulsive, according as the currents them- selves are in the same, or in opposite du'ections. In the current and in the magnet it assumes the condition of tangential force ; and in magnets and their particles it produces poles.

The author announces that he intends shortly to develop, in an- other series of these researches, some further views which he enter- tains concerning the nature of electric forces and electric excitation in connexion with the theory he has here advanced.

The Society then adjourned over the Easter Recess to meet again on the 26th instant.