242 



Prof. E. Wilson. 



[Jan. 7, 



Ho 



3*97 was observed at 2 million periods per second. It is possible, 

 therefore, that some residual charge has already come out at 2 million 

 periods per second. 



When the glycerine was warmed up to atmospheric temperature 10° C. y 

 it still remained solid, and its dielectric properties were examined at 

 this temperature. The resistance of the condenser was 216000 ohms, 

 whether the time of contact was 0*00002 or 0*011 second, and this is 

 about 3| times the resistance at 10° C. when the glycerine was in the 

 liquid state. No residual charge comes out between the above times. 

 At 2 million periods per second the specific capacity of this solid 

 glycerine at 10° C. is 6*67. By the method described previously* 

 the specific capacity is 16 at 50 periods per second. The specific- 

 capacity in the liquid and solid states at 10° C. varies approximately 

 as the conductivity for long times. The residual charge comes out at 

 times less than 0*00002 second, whether the glycerine be liquid or solid 

 at 10° C. 



Finally, the condenser 

 was frozen in carbonic acid 

 snow in ether, and the con- 

 ductivity at - 81° C. is shown 

 by the curve No. 2 in the 

 figure. The final conduc- 

 tivity is less, and the area is 

 less than given by the curve 

 No. 1. This difference is due 

 to the lower temperature for 

 curve No. 2. Fleming and 

 Dewar have shown that the 

 specific capacity of glycerine 

 for long times changes very 

 rapidly with its temperature 

 between - 50° and - 100° Pt. 

 The specific capacity at 

 — 81° C. was found to be 

 3*8 at 2 million periods per 

 second. 



During the freezing pro- 

 cesses above referred to the 

 conductivity of the glycerine- 

 was observed at different 

 temperatures. The results 

 are given in the accompany- 

 ing table. It is noteworthy 

 that for time 0*00002 second 

 A, vol. 189 (1897), p. 118. 













■ 



















5 -01 



Time of ConC&cS in Seconds. 



* Hopkinson and Wilson, 1 Phil. Trans. 



