88 CONDENSATION OF VAPOR AS INDUCED BY NUCLEI AND IONS. 

 TABLE 39. Distributions of vapor nuclei in dust-free air. Bar. 75.9 cm.; temp. 21. 5 C. 



56. Remarks on the table. These results are constructed in figs. 28 

 and 29 in different scales, the nucleation of fig. 29 being on a scale 100 

 times greater, so that it may be in keeping with the very low nuclea- 

 tions. As a whole the figures are very closely like the above, though a 

 different apparatus was used. The line for dust-free air and vapor nuclei 

 here showed a tendency to transcend large green coronas, distinctly 

 entering the violet of the first series; but as the coronas are filmy the 

 measurement is correspondingly difficult. Over 2,000,000 vapor nuclei 

 are registered by the present method in the extreme case. 



In general, however, apparatus II shows fewer nuclei than apparatus 

 I under like conditions of exhaustion. Thus at ^3/^ = 0.375, n 250,000 

 for I and n = 500,000 for II; at higher exhaustions, dp 3 /p = o.T,g, n = 

 800,000 to 900,000 for I, w = 600,000 for II; at op 3 /p = o.4o, n 900,000 

 to 1,000,000 for I and n= 1,200,000 for II; but here apparatus I is 

 already losing efficiency. 



Fig. 28 also shows the small nucleations due to radium I + 11 and 

 radium I to V, as compared with the enormous effect of X-rays in 

 proper positions. In the case of the intense X-rays, the striking rapid 

 upward sweep of the curve is noticeable in case of apparatus I as 

 compared with apparatus II. The asymptote is reached much more 



