B Professor Hare on the Electric Fluid. 



may give sparks with either. This is to me, nevertheless, a 

 complicated and unsatisfactory solution of the difficulty. 



Pursuant to the Franklinian theory, there can be no really 

 neutral point ; though the earth, as a reservoir, infinitely great, 

 compared with any producible by art, furnishes an invariable 

 standard of intensity, above and below which all bodies elec- 

 trically excited are said to be minus or plus *. It is perfectly 

 consistent with this theory, that sparks should pass, as they 

 are often seen to do, from conductors in either state ; not only 

 fi'om one to the other, but to bodies nominally neutralized by 

 their communication with the earth. As the difference be- 

 tween the electrical states of the oppositely electrified bodies, 

 must be greater than between either of their states and 

 that of the greater reservoii', the sparks between them will be 

 longer, but in all other characteristics will be the same. This 

 practical result is irreconcileable with the doctrine of two fluids, 

 according to which there can be no electricity in the earth, 

 which is not in the state of a neutral compound, formed by 

 these opposite electricities. For it would be an anomaly to 

 suppose the re-action between a neutral compound (a ter- 

 tium quid) and either of its ingredients, to resemble in inten- 

 sity, and in its characteristic phaenomena, the re-action which 

 arises between the ingredients themselves. As well might we 

 expect aqueous vapour to explode with hydrogen or oxygen 

 gas, as they do with each other. Nothing can be more at war 

 with the doctrine of definite proportions, of multiple volumes, 

 and every analogy established by the chemistry of ponderable 

 matter, than that two substances should combine, in every 

 possible proportion, and with precisely the same phaenomena ; 

 that they 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 phaenomenon 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 



* In some discussions which took place some years ago, between Mr. 

 Donovan and Mr.De Luc, in Nicholson's Journal, it was erroneously charged 

 against Franklin's doctrine, that he supposed that there was an absolute 

 state of neutrality. The doctrine of one universal fluid is to me obviously 

 irreconcileable with that idea, otherwise than as above explained. The 

 quantity of electricity in the globe, is as unalterable in any sensible degree, 

 as the quantity of water in the ocean ; and it may therefore be assumed to 

 be invariably the same. 



other, 



