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V. On the Direction and Mode of Propagation of the electric Force traversing 

 interposed Media. By George J. Knox, Esq., A. M., M.R.I.A. 



Read February 11, 1839. 



Whatever theory be adopted to explain the passage of the electric force 

 traversing an intervening fluid or solid substance not undergoing electrolyzation, 

 — whether we suppose it to originate in an inductive influence affecting the 

 circumambient ether of each particle of the substance in the line of direction of 

 the force, in whose alternate states of induction and equilibrium consists the pas- 

 sage of the electric current, (the rapidity of such changes constituting its inten- 

 sity,) while the vibratory motion produced in the particles of the ether on each 

 successive return to a state of equilibrium causes the phenomena of the light 

 and heat developed ; or whether we adopt the gross conception of the passage of 

 a fluid ; still it is important to determine if the electric force passes along the 

 surface of the interposed substance, or through the interior of its mass. 



Dr. Faraday* has shown that water will convey a feeble current of electricity, 

 without undergoing electrolyzation. To determine whether, under such circum- 

 stances, it will convey an electrical current along its surface or through its 

 substance, a glass tube, ten feet long, and half an inch internal diameter, bent in 

 the centre twice at right angles, was filled with distilled water. Two copper 

 wires, twenty feet long, having platina wires soldered to their extremities, were 

 inserted in barometer tubes of six feet in length, the platina wires being sealed 

 in the tubes within half an inch of their extremities. The other ends of the cop- 

 per wires were connected with a delicate galvanometer, and a constant battery 

 of successively one, two, four, &c. pair of elements. 



On immersing the platina wires in the liquid, their relative distances from 

 each other should decrease if the current passes through the water, but should 



• Series VIII. (970.) 



U 2 



