[mack.w] 



THERMO-LUMINESCENCE 



97 



Table 1 



It is seen that the above effect resembled polarization, but took 

 much longer to reach a maximum. To make sure that this factor 

 was eliminated the potential was applied at least 4 hours before any 

 readings were taken. 



Table 2 shows a typical set of readings to show the effect of 

 temperature on the conductivity. The calcite was maintained at 

 each temperature for at least 1>< hours so that any possible effect 

 of thcrmo-luminescence might disappear. 



Table 2 



Current 



Const. X — 

 T 



. 0061 K 

 .0110 K 

 . 0210 K 

 . 0284 K 

 . 0680 K 



Effect of Thermo-luminescence 

 Table 3 shows the effect of thermo-luminescence on the con- 

 ductivity of the calcite when it was suddenlv heated from -80°C to 

 22°C. 



Table 3 



Time 



No. of sees, per 100 scale 



division 



T 



Current = Const. X 



1 



22.0 sees. 



. 045 K 



