422 OHM ON THE GALVANIC CIRCUIT. 



places of the circuit, is equal to the sum of all the tensions situ- 

 ated between these tivo places, and consequently increases or 

 decreases exactly in the same proportion as this sum. When, 

 therefore, one of these places is touched abductively, the sum 

 of all the tensions, situated between the two, makes its appear- 

 ance at the other place, at the same time the direction of the 

 tensions must always be determined by an advance from the 

 latter place. All the experiments on the open pile, with the 

 help of the electroscope, instituted at such length by Ritter, 

 Erman, and Jager, and described in Gilbert's Annalen"^, are 

 expressed in this last law. 



All the electroscopic actions of a galvanic circuit of the kind, 

 described at the outset, have been above stated ; I therefore pass 

 at present to the consideration of the current originating in the 

 circuit, the nature of which, as explained above, is expressed 

 at every place of the circuit by the equation 



« = r- 



Both the form of this equation, as well as the mode by which 

 we arrive at it, show directly that the magnitude of the current 

 in such a galvanic circuit remains the same at all places of the 

 circuit, and is solely dependent on the mode of separation of the 

 electricity, so that it does not vary, even though the electric 

 force at any jilace of the circuit be changed by abductive contact, 

 or in any other way. This equality of the current at all places 

 of the circuit has been proved by the experiments of Becque- 

 relf, and its independency of the electric force at any de- 

 terminate place of the circuit by those of G. BischofJ. An 

 abduction or adduction does not alter the current of the gal- 

 vanic circuit so long as they only act immediately on a single 

 place of the circuit ; but if two different places were acted 

 upon contemporaneously, a second current would be formed, 

 which would necessarily, according to circumstances, more or 

 less change the first. 



The equation A 



shows that the current of a galvanic circuit is subjected to a 



* Vol. viii., xii., and xiii. 



+ PiuUetin universel. Physique. Mai, 1 82i>. 



\ Kastner's ^?'c/ii(', vol. iv. Part 1. 



