Dielectric Constants of certain Frozen Electrolytes. 305 



Dielectric Constant of Sulphate of Copper. 



(10 per cent, solution.) 



Frequency of contact-maker 121. Galvanometer deflection when 

 condenser has air as dielectric = 3"91 cm. for 100 volts. 

 Temperature G-alYanometer 



in platinum 

 degrees. 



deflection 



Dielectric 





in centimetres, constant. 



Observations. 



— Lvv ^ 



10-38 



2-57 



Charging volts 1004. 



-163-0 



1925 



443 





-133-2 



12-70 



16-40 



Charging volts 19- 7. 



-125-2 



1-25 



22-20 



Charging volts 1*43. 



-117-5 



2-45 



43-80 



Condenser warmed up in air out 



-110-7 



3-45 



61-50 



of the vacuum vessel. 



-93*3 



7-90 



142 ? 





-87-8 



9-84 



174-0 ? 







Dielectric Constant of Potassic Cyanide. 







(5 per cent, solution.) 



-197-2 



11-45 



2-85 



Charging volts 100*4. 



-168-8 



1-35 



24-10 



Charging volts 1'43. 



— Ib2*8 



1-95 



34-80 



Condenser warmed up in air out 



-139-1 



915 



163 ? 



of vacuum vessel. 





Dielectric 



Constant of Per chloride of Iron. 

 (Saturated solution.) 



-198-8 



13-37 



3-34 



Charging volts 100'4 



-162-7 



14-25 



3-56 





-144-9 



15-65 



3-91 





-1338 



333 



4-23 



Charging volts 19 - 8. 



The above observations are set out in curves in fig. 3. 



It will be seen that in each of the above three instances the 

 dielectric constant falls to a value, near to 3, at the temperature of 

 liquid air, but rises very rapidly in the case of the potassic cyanide 

 solution, less rapidly in the case of the copper sulphate solution, and 

 still less fast in the case of the ferric perchloride solution as the 

 temperature rises. 



As regards the electrical resistance, the following tables show 

 approximately the kind of variation which takes place, but these 

 figures are only approximations ; they include the leakage of the leads 

 and vibrating contact maker, which, though very highly insulated, 

 are not infinite in resistance. Hence these figures merely show the 



