214- Dr. Hare on the Difference between 



words, directly as the velocity. But what is to create inequality 

 of velocity when the channel, a wire for instance, is of the same 

 size and nature in both cases ? When the same fluid is in 

 question, the velocity will be as the forces by which it may be 

 impelled. The only forces to which electricity has ever been 

 alleged to be liable, as far as I am informed, are either the 

 self-attractive or self-repulsive power of its own particles, or 

 their attraction for other matter. It will be admitted that the 

 intensity of these forces must, in the case of electricity, as in 

 that of caloric or light, be as the quantity to the containing 

 space ; and consequently, that it would be unreasonable to al- 

 lege that the reciprocal repulsion of the electric atoms, or their 

 attraction for other matter, and consequently any velocity 

 thence arising, should not be in proportion to the state of con- 

 densation from which they may be liberated. 



If the superior velocity displayed by electricity generated by 

 friction be the cause, not the consequence of greater intensity, 

 how are we to account for the superior velocity? 



According to the doctrine of Uu Fay, electricity is retained 

 upon the surface of a charged pane by the reciprocal attraction 

 of the heterogeneous fluids. According to the Franklinian 

 doctrine it is retained by its attraction for the negative surface, 

 on which side this attraction is not counterbalanced by repul- 

 sion from other electricit}'. When the circuit is completed 

 by a conductor, according to the one doctrine, a surcharge on 

 the one side is translated to the other ; while, according to the 

 other doctrine, two heterogeneous fluids rush from the surfaces 

 in which they are previously accumulated in excess, to enter 

 into combination, and, at the same time, to restore the equili- 

 brium of the surfaces on which they have been respectively de- 

 ficient. But according to either hypothesis, wherefore should 

 the forces be greater for electric matter when generated by one 

 means, than when produced by another ? Why should a mass 

 of electric matter evolved in a difluse state by a machine, or 

 from a cloud, rush like a bullet through conductors, which are 

 almost impassable to the same fluid when evolved from a state 

 of extreme density within a simple galvanic circuit? 



During the process of exciting an electric battery, the elec- 

 tricity previously existing equally on both sides of the glass 

 is so transferred from one side to the other, that the one be- 

 comes as much negative as the other becomes positive ; and it 

 must be evident that the intensity will be limited by the extent 

 of the force by which this transfer is effected. It is difficult to 

 conceive that merely by a change of capacity arising from fric- 

 tion, a force should be generated at all comparable to that 

 which the electric matter must exert, in escaping, according 



