50 



OF Calicite. — By W. J. Jackson, M. A. 



% 3 y^ ' 



2. I ill 



Jio JZO J'O 34-0 



flG.4, 



//. Polarisation and Depolarisation 



The potential was applied to the crystal for 8 hours. After 

 disconnecting the battery the crystal was earthed and the 

 depolarization current measured by the electrometer. This 

 current plotted against time gives what is designated here as 

 the deplolarization curve. 



Considerable light is thrown on the conduction of electricity 

 through the calcite crystal by a study of these curves. 



From the data obtained it can be said that probably a 

 space charge exists near the elctrodes or possibly throughout 

 the crystal. The experimental facts also give evidence of a 

 displacement current and also a conduction current through 

 the crystal. 



