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ROYAL SOCIETY OF CANADA 



way the two outer ones. With such an arrangement, the magnitude of 

 the charge acquired ( — 94 millivolts) was about the same as the maxi- 

 mum values for each combination separately, namely, 85 and — 91 



millivolts {vide Table I, Nos. 25, 26, 27. See also Xos. 4, 14, 15, and 

 compare Figs. 3 and 8). 



The maximum value, it will be seen (vide Table I) varied greatly 

 with different combinations, and also was different at different times 



TABLE V. 



Cylinder— Tin No. 1 + Aluminium paint. 

 Without radium. 



of observation for the same combination. A good example of this latter 

 effect is to be found on the case of lead No. 1 in lead No. 2 (vide 

 Table 1, Nos. 4, 5, 6, 7, 8 and 9). Shortly after the cylinders had 

 been cleaned the maximum negative charge acquired was 46 millivolts, 

 one day later the value was 32, four days later 27, and twenty days 



