DECAY OF PHOSPHORESCENCE PRODUCED BY HEATING. 



95 



ing no measurable intensity or else no maximum. The relation between 

 the maximum intensity and the temperature, beyond the fact that the 

 intensity increases with the temperature, is not clear. 



40 Sec 



Fig. 95- 

 Maximum intensity vs. time of maximum intensity measured from the beginning of heating. 



For description of curves see Fig. 94. 



Fig. 96. 



Maximum intensity vs. length of excitation. The temperature of the furnace and the time between the 

 end of excitation and the beginning of heating are as follows: 

 21.6 sec. Curve //, 200 O, 21.9 sec. 



41-7 1. " 41-5 



81.4 J, " 81.6 



161. 6 K, " 161. S 



321.0 L, " 3217 



636.0 

 II55-0 



Fig. 97- 



Maximum intensity vs. temperature of furnace. The length of excitation and time between end of 



excitation and beginning of heating are as shown herewith. 



In an earlier paragraph mention was made of the existence of two bands in 

 the phosphorescence spectrum of the sample of Sidot blende used in this study . 



