THE SMITHSONIAN INSTITUTION. 379 



has shown, in the paper cited above, that tlic strength of the current 

 which passes through a liquid may he calcuhited hy formula, (2), and 

 l)e]ievos he has thus proved the existence of resistance to transition. 



Ohm, Vorselman de Heer, and other physicists, opposed this hypo- 

 thesis, and ascribed the above mentioned anomalies to a galvanic 

 poIa?'ization of the voltameter plates, which acts in opposition to the 

 electro-motive force of the battery. Denoting this force by E, the 

 strength of current, after inserting a voltameter, would be, according 

 to this view, 



E - 6 . (3) 



e donating the electro-motive opposing force in the voltameter, the 

 other letters retaining their former signification. 



At n times the distance of the plates from each other, the strength, 

 according to this view, would be 



E— e (4) 



S':=: R 4" ^"'^ 



Lenz treats of this subject again in volume LIX of Poggendorff's 

 Annalen, p. 229. A new series of experiments on the strength of the 

 currents with inserted voltameters is compared with formulas (1) and 

 (3) ; and Lenz finds that both satisfy the observations, and that the 

 changes in the strength of currents produced by the voltameter can 

 be made to accord with Ohm's law, as well by the hypothesis of a re- 

 sistance to transition as by that of an electro-motive opposing force at 

 the electrodes. 



Thus this investigation of Lenz leaves the question undecided, while 

 he himself holds the opinion that galvanic polarization is more prob- 

 able than resistance to transition. 



From the form in which Lenz combined his experiments, no decision 

 could be expected ; but, with another mode of considering this sub- 

 ject, this would not have been the case. We need only determine the 

 simple electro-motive force of a battery once with metallic circuit, and 

 then, with the voltameter inserted, to find whether or not an electro- 

 motive opposing force appears in the voltameter. 



A series of experiments, which I made for the purpose of rendering 

 the solution of the question apparent, gave the following results : 



Six zinc and carbon elements formed the battery. The tangent 

 compass inserted in the circuit gave 



For insertion of 46° deflection. 



For insertion of 49 metres of standard wire 30 " 

 Consequently the value of the electa'o-motive force of the battery is 



E = 4366. 



A similar experiment, in which a brass wire was inserted, equal to 

 29.2 metres of the standard wire, gave 



E — 4479 ; 

 then the mean is 



E =: 4422. 



