Page:Scientific Monthly, volume 14.djvu/558



From this point of view, the charges of A and B in the above experiment were merely manifestations of some condition in the medium between A and C and between B and D. If A assumed a larger proportion of the total electrification than B, it was because induction took place more freely between A and C than be tween B and D. Faraday accordingly said that sulphur had a greater capacity for electrical induction than air, and that if the inductive capacity of air were taken as 1, the inductive capacity of sulphur would be greater than 2.24.

It may be interesting at this point to consider briefly the difference between the views of Cavendish and Faraday. Cavendish believed all bodies to contain an unknown quantity of a single electric fluid, and that this fluid was always under some kind of external pressure and that in conductors it always flowed toward the region of least external pressure and could be in equilibrium only when the external pressure was everywhere the same over the surface of the conductor or system of conductors in which the fluid was confined. From his point of view, the reason that A took a greater charge than B in the Faraday experiment was that the external pressure on a given charge was less around A than around B, and hence that an excess of fluid would flow into A until this external pressure was equalized upon the fluid in the two spheres.

Faraday attributed the state known as electrification not to any changed condition inside the charged conductor, but wholly to