A letter to Prof. Faraday. 7 



the charging apparatus. Discharge is the return of the parti- 

 cles to their natural state, from their state of tension, whenever 

 the tiDO electric forces are allowed to he disposed of in some other 

 direction.''^ As you hai^e not previously mentioned any particu- 

 lar direction in which the forces are exercised during the preva- 

 lence of this constrained condition, T am at a loss as to what 

 meaning lam to attach to the words "some other direction." 

 The word soQue, would lead to the idea that there was an uncer- 

 tainty respecting the direction in which the forces might be dis- 

 posed of; whereas it appears to me that the only direction in 

 which they can operate, must be the opposite of that by which 

 they have been induced. 



The electrified particles can only " return to their natural state" 

 by retracing the path by which they departed from it. I would 

 suggest that for the words "^o be disposed of in some other di- 

 rection,'''' it would be better to substitute the following, " to com- 

 pensate each other by an adequate communication.'''' 



Agreeably to the explanation of the phenomenon of coated 

 electrics afforded in the paragraph above quoted (1300), by what 

 process can it be conceived that the opposite polarization of the 

 surfaces can be neutralized by conduction through a metallic 

 wire ? If I understand your hypothesis correctly, the process by 

 which the polarization of one of the vitreous surfaces in a pane 

 produces an opposite polarization in the other, is precisely the 

 same as that by which the electricity applied to one end of the 

 wire extends itself to the other end. 



I cannot conceive how two processes severally producing re- 

 sults so diametrically opposite as insulation and conduction, can 

 be the same. By the former, a derangement of the electric 

 equilibrium may be permanently sustained, while by the other, 

 all derangement is counteracted with a rapidity almost infinite. 

 But if the opposite charges are dependent upon a polarity indu- 

 ced in contiguous atoms of the glass, which endures so long as 

 no communication ensues between the surfaces ; by what con- 

 ceivable process can a perfect conductor cause a discharge to 

 take place, with a velocity at least as great as that of the solar 

 light ? Is it conceivable that all the lines of " contra-induction" 

 or depolarization can concentrate themselves upon the wire from 

 each surface so as to produce therein an intensity of polarization 

 proportioned to the concentration ; and that the opposite forces 



