122 



CONDENSATION OF VAPOR AS INDUCED BY NUCLEI AND IONS. 



TABLE 50. Fog chamber standardized with radium. Bar. 76. 2 cm.; temp. 25.7 C.; 

 water nuclei precipitated. Exhaustions above the fog limit of dust-free air. dp 3 /p = 

 o . 290 to o . 293 ; factor i . 22-1 . 23. 



'wrcor. 2 Radium removed. Corona glimpsed at j)P 20.4. 



These data are given in fig. 40,* which also contains the observed 

 values of i / n and the corresponding computed values of i / n if b = o . oo 1 4. 

 If the values of b are computed from the means of successive pairs of 

 measurements at different times /, the data under b "successive" are 

 obtained. A somewhat irregular increase is observed as n decreases. 

 If the first observation be combined with the fourth, etc., the values are 



=o.29 6=0.0029 



34 



36 



4i 



or a mean value 6 = 0.0033, if the last observation be ignored, since 

 the coronas are just visible here. 



If the electrical datum 6 = 0.0014 be correct, the present nucleations 

 n are to be increased on the average, 0.0003/0.0014 = 2.3 times; if the 

 last datum for b were included, much more. This is quite unreasonable. 

 One must conclude, therefore, that b for nuclei is larger than b for ions 

 or that an ion, acting as a nucleus in a saturated atmosphere, decays 



*The data of fig. 40 are constructed from an earlier computation not differing essen- 

 tially from table 50. 



