C. Bams — Ionization of Water Nuclei. 



113 



9. Results %oiih an Elliott Electrometer. — For reasons 

 which need not be stated here, the electrometer of modern 

 type above, in which the charge is imparted to the needle 

 through the suspension, notwithstanding its sensitiveness and 

 low capacity, is not adapted for further experiments. Accord- 

 ingly the data of the following table were obtained with an 

 ordinary electrometer, with the quadrants permanently charged 

 with a water battery. The core of the tubular condenser com- 

 municated with the needle. This adjustment was chosen because 

 the leakage here was relatively smaller, though the high 

 capacity of needle, jar and condenser is unfavorable to sensi- 

 tiveness. The table contains results in which the potential of 

 the core of the condenser was altered in steps of one half. 

 Care was taken to determine the insulation immediately before 

 and after each measurement with the nucleated medium. The 

 leakage was always greater at the beginning than at the end, 

 which is the usual phenomenon of absorption and release of 

 charge in the insulators. If any trace of radio-activity occurred, 

 it would be obscured by this phenomenon. 



The results of these observations may be summarized as 

 follows : 



Table IV. — Charges of water nuclei. dV/dt'= 21it/min. Capacity 409 cm . 

 Deflection of the electrometer, s. 

 Leakage ds/dt per 2 m 



Hectroineter 

 charge. 



+ at 

 81 volts 



Before, 

 cm. 



•13 



During 



nucieation. 



cm. 



•64 



After. 

 cm. 



•09 



Current 



C(dE/dt) 



xlO 11 . 



amperes. 



1-33 



n 

 xlO- 6 . 



1-72 



— at 

 81 volts 



•17 



•39 



•06 



•67 



•87 



+ at 

 40 volts 



•10 



•67 



•06 



1-47 



1-91 



— at 

 40 volts 



•11 



•34 



•05 



•64 



•84 



+ at 

 20 volts 



•08 



•63 



•03 



1-45 



1-89 



— at 



20 volts 



•06 



.27 



•02 



•57 



•74 



From these, since n — (clE/dt) (7/16*7 e V, the results of the 

 last column follow, giving for the mean currents 



at 81 volts n = 1*3 X 10 6 

 at 40 1*4 



at 20 1-3 



