62 CONDENSATION OF VAPOR AS INDUCED BY NUCLEI AND IONS. 



The amount of exhaustion was equivalent to the volume ratio v 1 /v = 

 1.29. Thus the number of ions in the fog chamber at atmospheric pres- 

 sure was N = 611,000 per cubic centimeter for the uncharged core. 



TABLE 21. Fall of potential and currents. V' conduction leakage ; V" due to presence 

 of radium. Wires not piped. Four-second intervals between observations. 



The value of 6=i.iXio 6 is taken from Professor Rutherford's book. 

 The source of light for the coronas is part of a Welsbach mantle, as usual, 

 and the old constants of coronas were used, since it is a part of the purpose 

 of this paper to test those constants. The volume of the fog chamber was 

 estimated at 51,000 c. cm. In the first experiments the effect of the 

 gamma rays penetrating into the air on the outside of the fog chamber 

 was neglected and the data, summarized from table 21, on using different 

 condensers, were as follows, all data being given in electrostatic units. 

 C denotes the capacity of the system, V the drop of potential per second, 

 7 the corrected current passing through the condenser-fog-chamber. 



