920 Effect of Electric Current on Photo-Electric Effect. 



described : — (1) Temperature effect ; (2) an orientation of 

 the elementary crystals of the metal. 



1. The possibility of temperature making such a large 

 change is extremely unlikely. In fact, with pure metals, it is 



Eur. 3. 



IO 20 30 40 50 60 70 



Current through plate in milliarnpQres 

 Sputtered bismuth plate (on mica). 



generally accepted that temperature produces no change in 

 the photo-electric effect. Moreover, in this experiment, 

 currents which produced very considerable increases in the 

 photo-electric current caused only a fraction of a degree rise 

 in the temperature. 



