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cally polarized, and the strength of current was slowly raised to 

 2 mA., at which the potential amounted to —0,405 Volt. When 

 air was blown through along the electrode, the potential did not 

 change more than 10 mV; the same occurred when the liquid was 

 stirred, from which follows that the activity of the chromium was 

 not caused here by a change in concentration of the liquid in 

 contact with the metal. After the current had continued to pass 

 throughout the night, the strength of the current had increased to 

 3.28 mA., and the potential had fallen to — 0,513. Accordingly the 

 electrode was very active now. The solution of KCl was then 

 Biphoned off, and replaced by fresh solution. The electrode remained 

 active, though the potential rose a little, viz. from — 0,513 to 

 — 0,472. Here too it appears that the activity of the chromium 

 was not the consequence of a change in the concentration of the 

 liquid. The chromium generated small bubbles of hydrogen. Also 

 when the metal was brought in contact with a platinum wire, it 

 remained active. In this the hydrogen continued to develop at the 

 chromium. When the current was broken, the potential was — 0.613, 

 and fell to — 0,642 in 15 minutes. 



Now the electrode could resist 1 mA without becoming passive, 

 and the current could be made stronger pretty quickly, in 20 minu- 

 tes from 1 mA to 3.6 mA, without the activity being lost. 



Accordingly the anodic current could remain interrupted for this 

 electrode for 15 minutes, the activity being maintained. 



After the anodic current had been first carried up to 3.6 mA 

 again, at which the potential amounted to — 0,421, it was cathodi- 

 cally polarized with 50 mA for 15 minutes. This took place in 

 another solution of KCl. The anode was placed in a porous vessel, 

 so that the liberated chlorine did not get in contact with the chro- 

 mium electrode. When the electrode was again brought in the original 

 solution of KCl, the potential was strongly negative in consequence 

 of the hydrogen charge, — 1.09 V. Then this electrode was anodi- 

 cally polarized with 0.5 mA. In an hour the potential rose to 

 -}- 0.512 V. While therefore without previous cathodic polarisation 

 the electrode could bear anodically 1 mA without becoming passive, 

 it already became passive with 0,5 mA after cathodic polarisation. 

 After interruption of the current this electrode again obtained an 

 active potential, viz. — 0.614 V. 



become smaller. When afterwards the zinc was removed, the potential rapidly rose 

 to - 0.35 V, after which it fell again to its original value — 0.54 in three minutes. 

 The decrease of the anodically polarizing current had consequently given rise 

 here to a very considerable rise of the potential. 



