NUCLEI IN ALCOHOL VAPOR. II9 



nuclei in the exhausted fog chamber. It is assumed, therefore, that the 

 nuclei are reproduced more quickly than they can be withdrawn by the 

 exhaustion. Measurement of s is not very satisfactory, as the coronas 

 are blurred and accompanied by dense fogs and changes rapidly on 

 subsidence. The effect of X-radiation is shown in parts III and IV of 

 the table leading to the same terminal corona as for the non-energized 

 vapor. 



The results have been given graphically in figs. 55 and 56, the former 

 referring to coronas (s) , the latter to nuclei (n) , in connection with earlier 

 results for media of water-air and water-carbon dioxide, the same con- 

 densation apparatus and method underlying all experiments. One 

 may notice at once that in the cases C0 2 -water and air-water, both for 

 the non-energized and for the energized state, the observed data would 

 be obtained by shifting the air-water diagram as a whole to the right, 

 as if the cooling in case of C0 2 -water vapor were less efficient. The 

 graphs are of the same kind, nearly parallel, and all of them (energized 

 or not) terminate in the same asymptote or large green-blue-purple 

 corona. 



The alcohol curves are different from these chiefly in three respects: (1) 

 Though the graphs both for the non-energized and energized states again 

 terminate in the same asymptote, this is not the green-blue-purple 

 corona, but the white-yellow corona which lies slightly below it; (2) the 

 curves as a whole lie with a somewhat larger slope in a region of much 

 lower exhaustions (dp); (3) the number of nuclei caught in alcohol 

 vapor is relatively very large. The second and third observations have 

 already been discussed. The first deserves especial consideration. The 

 question occurs at once why both the energized and the non-energized 

 curves should terminate in the same final corona, irrespective of the 

 size of the nuclei, and why this should be lower for alcohol than for 

 water. For the ionized state one might infer that the total number of 

 ions has been precipitated, as is actually the case for low ionization; 

 but if for strong ionization this were true for alcohol vapor it could 

 not be true for water vapor where the number of ions caught is less than 

 one-half the number in alcohol. In general, it is improbable that the 

 terminal corona for ions should in such a case be the same as the terminal 

 corona for colloidal nuclei. 



The explanation which seems plausible to me is this: Each nucleus 

 must drain the air of its supersaturated moisture within a certain radius, 

 large as compared with the size of the nucleus and increasing in the 

 lapse of time. 



A limit of the phenomenon will be reached when for an indefinite 

 number of graded nuclei the enveloping spheres free from supersatu- 



