UTAH ACADEMY OF SCIENCES 161 
THE RESISTANCE OF THIN METAL FILMS 
WHEN EXPOSED TO ULTRA 
VIOLET LIGHT. 
BY ORIN TUGMAN. 
When a metal is exposed to violet light, negatively 
charged bodies are emitted with velocities proportional 
to the frequency of the light waves. These electrons are 
emitted in all directions. Inasmuch as the electrical 
conductivity of a metal is a function of the number of 
free electrons in a metal it is expected that the resistance 
of a metal will be changed by the action of light. If the 
metal is thin the number of electrons liberated by the 
light may be large enough in proportion to those moving 
in the ordinary conduction to make a measurable effect. 
The conductivity is measured by an electrometer. 
The metal film is sputtered in vacuo and measured in 
place. 
