﻿excited by the Alpha Rays from Polonium. 831 



Table XL 



Air in Apparatus. 



Fatigued carbon electrode. Charge on polonium = 84 volts. 



Pressure of air in 



vessel. 



Time from initial 



reading taken 7 minutes 



after starting pump. 



Current to 

 electrode. 



•006 ram. 

 •004 „ 

 •002 „ 

 •002 „ 



•ooi „ 



minutes 



1 ,, 



5 » 

 15 



30 



663 mm. 

 45-3 „ 

 29-3 „ 

 21-3 ., 

 173 „ 



Fig:. 6. 



50 75 



Trme in Minutes. 



(00 



US 



to the results in Table X., while the lower curve refers to 

 Table XL A comparison of these curves with the curves 

 shown in fig. 4 makes it plain that there was a much greater 

 recovery of the carbon fatigue when it was left in vacuo a 

 very short time and then surrounded by air, than when it 

 was left for a long time before being surrounded with air. 



This pointed to the probability that the gas occluded in 

 the carbon was the cause of the large decrease with the time 



