124 



CONDENSATION OF VAPOR AS INDUCED BY NUCLEI AND IONS. 



so that they withdraw more and more fully beyond the given range of 

 supersaturation applied, the second part of these occurrences would also 

 be accounted for; but the assumption is not probable. 



73. Exhaustions below the condensation limit of dust=free air. 



It would follow from what has just been stated that if the drop of 

 pressure is lower, the values of b obtained must be larger ; for not only are 

 few of the ions caught, but the diminution of bulk (virtually) which may 

 accompany the decay would place them sooner out of reach of the given 



!0 



20 



10 fa* 20 



FIG. 41. (a) Decay of ionization in fog chamber in 

 lapse of seconds, n being number of nuclei per cubic 

 centimeter. (6) i/n in the lapse of seconds ob- 

 served and computed with 6 = 0.0014 when n is ex- 

 pressed in thousands per cubic centimeter. 



exhaustion as the interval of decay increases. Table 51 contains ex- 

 periments of this kind, and they are reproduced in fig. 41, the data, 

 however, being again constructed from an older computation which 

 suffices for the present purposes. The relative drop in the first series 

 is about at the fog limit of dust-free air, while in the second series it is 



