310 



Prof. R. B. Clifton on the 



[June 14, 



With condenser-plates of iron and copper carefully cleaned I obtained 



Fe | Cu = 0-0774 C. 



0-0717 C. 



0-0745 C. (Mean.) 



With condenser-plates of zinc and copper carefully cleaned immediately 

 before commencing the series of measurements the following results were 

 obtained : — 



Zn | Cu = 0-6180 C. 



0-6238 C. 

 0-6172 C. 

 0-6204 C. 



0-6198 C. (Mean.) 



In these experiments the circumstances were altered as much as pos- 

 sible, the condenser-plates were adjusted at different intervals, and the 

 plates were in some cases separated slowly, and in others as rapidly as 

 possible ; yet the greatest amount of variation in the measures obtained 

 scarcely exceeds one per cent. 



These two measurements lead, by Volta's law, to 



Zn | Fe = 0-5453 C. 



Direct experiments with condenser-plates of zinc and iron gave the 

 following results : — 



Zn | Fe = 0-5228 C. 



0-5329 C. 

 0-5198 C. 



0-5251 C. (Mean.) 



Unfortunately in these experiments the plates were not cleaned imme- 

 diately before the measurements were made, and the zinc plate was very 

 slightly oxidized, so that this series must give a value for Zn | Fe below 

 the true value. For this reason more confidence is to be placed in the 

 result deduced from the experiments with Zn and Cu and with Fe and Cu 

 than in that obtained by the last series. 



When mercury acted as the lower plate of the condenser and the 

 upper plate was of iron, I obtained 



Fe | Hg=0-23144 C. 



The above-mentioned results lead, then, to the following : — 



Fe | Cu =0-120 . Zn 

 Zn | Fe =0-880 . Zn 

 Fe | Hg = 0-373 . Zn 

 Zn | Hg = 1-253 . Zn 

 Cu | Hg = 0-253 . Zn 



Cu. 

 Cu. 

 Cu. 

 Cu. 

 Cu. 



