CONDENSATION OF VAPOR AS INDUCED BY NUCLEI AND IONS. 



From these data it appears that above w= 200,000 nuclei dissipation 

 is due more and more largely to evaporation; below n= 2 X io 5 more and 

 more largely to subsidence. Above w=io 5 or d = 0.003 cm -. moreover, 

 the tube in part i remains permanently hazy and the fogs (if seen through 

 some thickness) quite black. 



TABLE 2. Persistence of solutional water nuclei. Shows number of exhaustions to 



clean with complete (apparent) subsidence. 



4. Slow spontaneous evaporation of fog particles. Vapor nuclei. We 



may now contrast with the preceding the evaporation of fog particles 

 precipitated on the vapor nuclei of dust-free air. Table 3 contains the 

 results arranged on a plan similar to the above. A slight difference of pro- 

 cedure is necessary, because the vapor nuclei are not caught in sufficient 

 quantity except at very high exhaustion. Moreover, these exhaustions 

 have no effect in removing vapor nuclei, as these are instantly reproduced 

 by the kinetic mechanism. The water nuclei, however, should be pre- 

 cipitated at an exhaustion less than the fog limit of dust-free air. Beyond 

 this the exact value of the exhaustion ratio ^ = 0.71 to o. 7 7 is of no import- 

 ance, because the ratio of successive nucleations, n'/n is usually less than 



