Ice as an Electrolyte. 



117 



An eloctromotive 



force of 



2-61 volts 



Now suddenly in- 

 creasing this to 

 4-35 volts 



gave a deflection of at a temperature of 



52-5 

 diminishing to 30' 1 



the deflection dimi- 

 nished to 

 39-5 



8°-3 C. 



-8°-3 C. 



It might have been expected that doubling the electromo- 

 tive force would have more than doubled the deflectioUj since 

 the diminution of resistance in a dielectric produced by time 

 of charging only proceeds gradually — whereas the deflection 

 only increased from 30' 1 to 39*5. This peculiarity is shown 

 more fully in the following Table, in which the readings just 

 before and after changing the battery-power are given, the 

 intermediate ones being omitted: — 



Electromotive force 2*61 volts. 

 Time. Deflection. Temperature, 



h m s 

 7 48 30 



30-1 



12^0. 



Electromotive force of battery increased to 4*25 volts. 



7 49 30 39-5 -12° 0. 



7 51 30 36-5 



Electromotive force increased to 8*7 volts. First swing off 

 the scale, but very soon grew steady on returning. 



7 52 53-1 -12°'2 C. 



7 53 50-5 



7 54 49-1 



First swing off 



Electromotive force increased to 17*4 volts. 



the scale. 



7 55 72-7 -12°-5C. 



7 56 69-0 



7 61 59-5 



Electromotive force increased to 28*71 volts. First swing off 

 the scale. 



8 2 76-5 -12°-8 C. 

 8 5 68-6 



8 6 67-2 -13°-0 C. 



Short-circuited the coppers on the two sides of the ice for 

 four minutes. 



