Hare on Electricity. 107 



^ley do with each other. Nothing can be more at war with 

 the doctrine of definite proportions, of muhiple volumes, 

 and every analogy established by the chemistry of ponder- 

 able matter, than that two substances should combine, in 

 every possible proportion, and with precisely the same phe- 

 nomena ; that ihey should be capable of neutralizing each 

 other, and yet eagerly act as if never neutralized. 



An argument in favour of the existence of two fluids, has 

 been founded on the appearance of two burs, when a card is 

 pierced by an electric discharge. This phenomenon is as 

 difficult of explanation, agreeably to Du Faye's Theory, as 

 Franklin's. If a current of electricity, flowing in one direc- 

 tion, should produce a bur, in piercing a card on the side 

 towards which it flows, two currents should be productive of 

 none, one current being precisely adequate to neutralize the 

 other, according to the premises. The appearance may be 

 explained by either doctrine, as resulting from intense at- 

 traction between the paper and the knobs transmitting the 

 discharge. 



It has been observed, in favour of the French theory, 

 that, when the hands are made the medium of a feeble dis- 

 cbarge, a shock is felt simultaneously in the fingers only of 

 each hand ; that,as the shock is made stronger, it affects 

 the wrist, the arm, and finally the chest. This is considered 

 as proving the operation of two distinct fluids; for, were 

 the shock the effect of one current, it would be experienced 

 equally, though feebly, throughout the whole of the 

 circuit. Admitting that such a current were necessary to 

 the discharge, agreeably to Franklin's theory, it ought to be 

 f&lt most in the fingers, where it is most concentrated, as 

 torrents flow with greater violence in proportion as their 

 channels are narrowed. A current passing from one coat- 

 ing of a Leyden jar to another, is far from being necessary 

 to restore the equilibrium of its surfaces. As soon as a cir- 

 cuit is established between them by the hands, the electri- 

 city in the hand which touches the negative surface, flows 

 into it to supply the deficiency ; while the hand which 

 touches the positive surface, receives from it a surcharge. 

 It is a case analogous to that of a syphon, in which a fluid, 

 forcibly displaced from the level, is suddenly relieved from 

 restraint ; both columns would move at the same time, and 

 with a velocity greater in any part, in proportion as the di* 



