IN A CLOSED GALVANIC CIRCUIT. 255 



such motion. The intensity of a galvanic current represents an 

 idea composed of many elements, and the moving force of the 

 current must be referred to the same elements. To this end it 

 is necessary to consider the matter more closely. 



Let a liquid at any place be divided into two compartments, 

 by means of a porous clay partition. Let both sides of the clay 

 partition be covered by metal plates, which exert an electric 

 tension (electromotive power) on each other. Let, for example, 

 one of these be a copper, the other a zinc plate, both being con- 

 nected, without the liquid, by a wire whose resistance to conduc- 

 tion is small enough to be neglected. The tension (E) generates 

 a galvanic current in the liquid through the porous partition, 

 whose intensity (i) is directly proportional to the tension (E), 

 and to the surface (o) of the partition, but inversely proportional 

 to the specific resistance (r) of the liquid used, and to the thick- 

 ness {d) of the partition, 



(i=const.g). ...... (1) 



By means of this galvanic current the liquid will be trans- 

 ported from the positive to the negative side of the porous j)ar- 

 tition, with a force equivalent to a certain hydrostatic pressure (h). 

 This pressure {h) is directly proportional to the intensity {i) of 

 the galvanic current to the thickness (d) of the partition, and to 

 the relative resistance (r) of the liquid, but inversely propor- 

 tional to the surface (o) of the partition. Hence 



(h = const'^Y ...... (2) 



By combining the equations (1 and 2), 



, Eo re? ^ T^ 

 A = const, const. — = . — =C.E, 

 rd 



it follows immediately that an electric tension present on both 

 sides of a porous partition, immersed in any liquid, transports 

 that liquid from the positive to the negative side, with a force 

 equivalent to a hydrostatic pressure directly proportional to that 

 tension^, 



* Without doubt the law here established under the supposition that porous 

 diaphragms are employed, is also immediately applicable, no matter what kind 

 of a transverse section be laid through the liquid traversed by the galvanic 

 current. 



