oiiM On the galvanic circuit. 471 



A and B, and at the same time 1 — - — for n, which is ner- 



2 m * 



mitted when m, as is usually the case, denotes a very large 



number, we obtain 



h. — md-^\u. 



Or when m is a very large numbei', and n not much greater than 

 d, we may, without committing any perceptible error, place 



A = m d, 

 B = —md, 

 in which is expressed the known law, that when two different 

 places of a voltaic pile are brought into connexion with the two 

 plates of an insulated condenser, each plate takes the same 

 charge as if the other plate, and the corresponding place of the 

 pile, had been touched deductively. At the same time our con- 

 siderations show that this law ceases to be true when u can no 

 longer be regarded as evanescent towards m d. This case would 

 occur if, for instance, two places, near the insulated upper pole of 

 a voltaic pile, constructed of a great number of elements, came in 

 contact with the plates of the condenser, while the inferior pole 

 of this pile remained in deductive connexion with the earth. 



The determinations hitherto given respecting the mode in 

 M'hich the galvanic circuit imparts its electricity to foreign 

 bodies, and ^vhich a^^pear to me to leave nothing more to be 

 wished for in the explanation of this subject, might, however, 

 give rise to researches of a very different kind, and of no slight 

 interest. For it is placed beyond all doubt, both from theore- 

 tical considerations, as well as from experiments, that electricity 

 in motion penetrates into the interior of bodies, and its quantity 

 accordingly depends on the space occupied by the bodies; while, 

 on the other hand, it is no less ascertained that static elec- 

 tricity accumulates at the surface of bodies, and its quantity 

 therefore is dependent on the extent of surface. But it would 

 hence result, that in the closed galvanic circuit, r in the above 

 formula." would express the volume of the circuit ; in the open 

 circuit, on the contrary, the magnitude of its surface, on which 

 point, in my opinion, experiments might decide without great 

 difficulty. 



22. We have hitherto kept in view a circuit on which the 

 Burrounding atmosphere exercised no influence, and which has 



2i 2 



