concerned in the Phenomena of ordinary Electricity, tye. 453 



time affirm that the current of electricity is only called into action 

 when the circuit is closed, which is not the case in the instance 

 under consideration. 



Beside the foregoing objections against adducing the Leyden 

 battery in support of the alleged efficiency of quantity to explain 

 the difference between voltaic and ordinary electric phaenomena, 

 it may be worth while to make some further animadversions. 



Various opinions have prevailed with regard to the nature of 

 electricity : some suppose that it is an imponderable transferable 

 elastic fluid ; others that it consists of two such fluids ; others 

 that it is not a transferable elastic fluid, but vibrations of a sta- 

 tionary fluid ; while others maintain that there is no fluid, and 

 refer the phaenomena to molecular vibrations of the electrified 

 substance. 



Be this as it may, those who believe in the existence of an 

 elastic fluid, or two such, have explained electrical phaenomena 

 by positive and negative electricity. The passage of one or two 

 electric fluids from one body to or through another, is called a 

 current, and the idea of a current naturally enough involves the 

 idea of quantity. It is thus that we talk familiarly of the enor- 

 mous quantity of electricity which must circulate in a current, 

 and which in an instant communicates a charge to a Leyden 

 battery. All this is very intelligible, although not satisfactory, 

 provided that such a fluid does really exist and that it flows in a 

 current, but no one has ever been able to prove these conditions. 

 In fine, when a Leyden battery is charged, we have no knowledge 

 of its being filled with anything ; all is conjecture : but a fos- 

 tered hypothesis has produced a kind of common consent that 

 it is full of a fluid. Now this position may be denied ; and it has 

 been questioned by no less a judge than Sir H. Davy, who in- 

 clined to the opinion that there is no specific fluid ; and Faraday 

 is far from discarding the same doubt. All arguments concerning 

 the identity of voltaic and common electricity, founded on quan- 

 tity and the instantaneous charge of a Leyden battery, must, in 

 that view, at once fall to the ground, and the contemplated proof 

 turn out a failure. 



Those who adopt the opinion that electric phaenomena are 

 produced by vibrations of some elastic medium, must admit that 

 as impulses communicated to elastic media will be transmitted 

 through them with uniform velocity, a momentary contact of a 

 Leyden battery with a voltaic series ought to throw the natural 

 electricity of the former into a state of vibration similar to that 

 of the electricity of the latter, in such a manner as air is supposed 

 to be thrown when it is made the medium of sound. If the 

 voltaic charge of the Leyden battery be of this vibratory kind, 

 the wonder of its instantaneous communication is at an end, and 



