﻿2G0 



Dr. J. Robinson on 



some time at zero potential, and, 3rd, after it had been exposed 

 at a positive potential. 



Table IV. 



Condition of Electrode. 



Current. 



Fresh • 



42 

 42 



13 



42 



i 



After an exposure to light for 5 minutes at a 1 

 potential of +10 volts J 



After an exposure to liglit for 5 minutes at 1 

 zero potential J 



Recovered Elect rode 



Table V. 



Condition of Electrode 



Fresh 



Exposed to light for 1 minute 



Eest of 7 minutes 



Exposed for 2 minutes 



Eest of 5 minutes 



Exposed for 3 minutes 



Current. 



40 

 25 

 42 

 18 

 41 

 18 



Table VI. 



Condition of Electrode. 



Current. 



Fresh 



88 

 34 

 68 

 34 

 51 

 58 

 63 

 71 

 78 



Fatigued for 5 minutes (at zero potential) 



Recovered for 5 minutes 



Fatigued for 5 „ 



Recovered for 1 ,, 



2 



3 „ 



5 „ 



11 , 





The general results of these experiments are (1) that a 

 metal is fatigued by exposure to ultra-violet light ; and after 



