372 G. Th. Fechner's Justification of the 



perpendicular to the coils, immediately after the closing, by 

 means of the method already sufficiently described elsewhere ; 

 and the circuit, immediately I'e-opened in order to avoid as 

 much as possible the decrease of action. Moreover, before 

 each new measurement the active condition of the zinc and 

 copper circuit was not only restored by being kept long out, 

 (vide on this subject my measurements of the galvanic cir- 

 cuit,) but even the zinc plates a a, were cleaned by filing. 

 If the power of the current without the interposed apparatus 

 was represented by 1000, it became on the insertion of the 

 intermediate apparatus : 



When the interposed apparatus was filled withl Q.QonK 



distilled water J 



with fuming sulphuric acid . . 64-685 



with diluted sulphuric acid . , 851*04- 



The last power could not be accurately measured on account 

 of the extreme velocity of the first oscillations, and probably 

 approaches much closer to the power without the interposed 

 apparatus than as stated. 



For the preparation of the dilute sulphuric acid I took, by 

 estimation, 1 volume of fuming sulphuric acid and 3 volumes 

 of distilled water. 



On employing platinum instead of zinc plates in the inter- 

 posed apparatus, 1 obtained the following relative current 

 forces according to the fluids it was charged with, by which, 

 the value of the current without the interposed apparatus 

 being again fixed at = 1000, 



When the apparatus was filled with concen-1 17-703 



trated nitric acid J 



with muriatic acid .... 2*5822 



with nitro-muriatic acid . . 338*34 



The nitro-muriatic acid was composed of about equal vo- 

 lumes of each acid (I did not however take the sp. gr.). It 

 is remarkable that the action in the nitro-muriatic acid did 

 not immediately after closing the circuit attain the assigned 

 magnitude, but was considerably weaker, but very quickly 

 rose to that magnitude, which circumstance I frequently ob- 

 served; while, in the experiment with zinc, sulphuric acid and 

 water, the power here stated was attained immediately. The 

 change, on which this increase depended, was an action of 

 the closure itself, since it was even indicated when the pla- 

 tinum plate had already stood for some time in nitric acid 

 previously to the closing, and was repeated at new closings 

 after intervening breaks. In the mean time it cannot be 

 ascribed to a gradual charging of the plate so far as by that 

 is understood a change of the electro-motive power, since by 



