492 



Mr. R. Appleyard on 



Table IV. 



Mercury Electrodes. 



Volts. 



Shunt, 



Deflexion, 

 1 min. 



Deflexion, 



i Megohms. 





obms. 



2 min. 





+ 150 



700 



287 



284 



i 11-9 



-150 



700 



294 



294 



11-6 



+300 



400 



342 



335 



11-6 



-300 



400 



351 



350 



I 11-3 



+450 



200 



269 



261 



11-3 



-450 



200 



273 5 



271 



11-2 



+ 600 



200 



358-5 



346-5 



11-3 



- 600 



200 



364-5 



360 



111 



+750 



140 



319 



317-5 



11-2 



-750 



140 



324 



319 



110 



+ 600 



200 



365-5 



355 



11-1 



-600 



200 



367-5 



362-5 



110 



+ 150 



700 



303-5 



302 



11-2 i 



-150 



700 



304 



302 



11-2 



After leaving the sheet for four hours, it was again placed 

 between the tinfoil electrodes, with the following result : — 



Table V. 



Tinfoil Electrodes. 



Load in 





Shunt, 



Deflexion, 



Deflexion, 





grammes 

 per cm. 2 



Volts. 



ohms. 



1 min. 



2 min. 



Megohms. 



22-3 



+300 



1000 



459-5 



466-5 



20-1 





-300 



1000 



498 



494 



18-6 



,, 



+450 



400 



366 



367-5 



J 6-3 



j. 



-450 



400 



377-5 



380 



15-8 



,, 



+ 600 



200 



291 



286 



13-9 





-600 



200 



292-5 



293 



13-9 



); 



+750 



200 



393 



384 



12-9 





-750 



200 



395 



393 



12-8 



>> 



+ 150 



1000 



2325 



232 



20-2 



}5 



-]50 



1000 



217 



212 



21-6 



543 



-150 



1000 



408 



408 



10-0 





-750 



100 



249 



246 



10-3 



" 



-150 



1000 



423 



422 



9-7 



The final three tests with the greater load were intended 

 to indicate the true resistance, the current therefore was not 

 reversed; they are seen to be fairly uniform, and they justify 

 the use of tinfoil electrodes for rough tests where mercury 

 cannot be obtained. The fact that these three values are all 

 lower than those given with the mercury apparatus on the 

 same afternoon (Table IV.) is probably accounted for by the 



