Ordinary and Voltaic Electric Fluids. 1 77 



arrives at the situation which produces the complete collapse 

 of the pith-balls, no spark can be obtained of even moderate 

 dimensions. When, although the quantity is much greater 

 than on the former instance, the length and even the diameter 

 of the spark is considerably diminished, remove the metallic 

 plate C D and the pith-balls will again diverge probably to as 

 great an extent as before; and by repeating the experiment, 

 the same results may be obtained under favourable circum- 

 stances for a considerable period. In this experiment the 

 pith-balls show the degree of what I denominate tension, which 

 at any time exists. We find also that as the plate CD ap- 

 proaches, the capacity for fluid is considerably augmented', that 

 when the plates are contiguous a large supply of fluid may be 

 added without producing any apparent or sensible effect; and 

 that in ratio with the contiguity of the plates so is the capa- 

 city. Hence may we infer, as stated by Dr. Faraday, "what 

 an enormous quantity of electric fluid is present in matter," 

 their atomic particles being at all times subject to the polari- 

 zing influence of each other, and at inappreciable or atomic 

 distances, and inducing thus an amazing capacity for, and 

 condensation of, fluid. 



In solution of the phenomena observable in the last expe- 

 riment, it will be found necessary to go back to the original 

 production of the fluid by the electrical machine. Upon the 

 first movement given to the cylinder by the friction of the 

 electric against the rubber, the positive condition of the cy- 

 linder and negative state of the rubber is universally admitted 

 to be the result. As long as these two surfaces remain in ap- 

 position the fluids are in a state of dissimulated or disguised 

 electricity, and no electrometer would be enabled to exhibit 

 any signs of electric action, although the quantity of fluid ac- 

 cumulated in each is the same as when separated. But as the 

 cylinder revolves, each portion, as it is rendered positive by the 

 action of the rubber, is carried to a considerable distance from 

 the same, and thus an entire removal of the one electrical 

 condition from its opposite state, or in other words, a separa- 

 tion of the antagonist forces is the consequence ; and it is after- 

 wards subject to polarizing influence only from remote bodies. 

 Now resulting from this separation of the forces a complete 

 suspension is given to their attractive influence upon each 

 other, polarizing influence being diminished according to the 

 square of the distances. The fluid thus set at liberty now 

 begins to exhibit the peculiar properties of "free" fluid or 

 ordinary electricity. The first and main peculiarity which it 

 manifests is the mutual repulsion of its own particles as a re- 

 sult of this repulsion ; we have the electrical particles separa- 



Phil. Mag. S. 3. Vol. 24. No. 158. March 1844. N 



