882 M. W. Beetz on the Magnitude of Galvanic Polarization, 



This force varied very little with the increasing intensity of 

 the decomposing current. 



Further, platinum was used for the negative, and zinc for the 

 positive electrode ; the former being immersed in hydrochloric 

 acid and the latter in dilute sulphuric acid, so that both liquids 

 were in contact with a cylinder of porous clay. The result was, — 



III. 



Polarization, Pt(H). 



1908 

 19-23 

 20-26 

 17-36 

 19-48 



Mean . , 19-08 



. In a similar manner, by employing platinum immersed in 

 hydrochloric acid for the positive, and copper immersed in a 

 solution of sulphate of copper for the negative electrode, the fol- 

 lowing numbers were obtained: — 



IV. 



Polarization, Pt{Cl). 



10-46 

 9-79 

 10-34 

 1003 

 10-20 

 10-78 



Mean . . 10-27 

 Hence the — 



Polarization by chlorine = 10-27 

 hydrogen =19-08. 



Therefore the polarization by both gases is— 



Calculated. Observed. 



29-35 28-83 



Consequently, the charges have here been added together ; hut 

 the absolute magnitudes of these charges are the same as those 

 which I before found for the electromotive forces of chlorine and 

 hydrogen in a gas battery ; for the latter, when reduced to the 

 present unit, would be 10*10 and 17*89*. 



That such a near coincidence should take place in the decom- 

 position of hydrochloric acid, and not in that of dilute sulphuric 



* Phil. Mag. S. 3. vol. xxxvi. p. 81. 



