NUCLEATION CONSTANTS OF CORONAS. 



TABLE 37. Radium I, 100 mg. io,oooX, and radium II, 10 mg. 2oo,oooX compared. 

 Bar. jG.ycm.; temp. 20 C.; 3p 3 = 22 .9 cm.; 3p 3 /p = o. 299; i>,/-u= i . 287. 



glass end. Observations were made with both eyes below c, as this posi- 

 tion showed the largest coronas. The marked reductions of size for the 

 other positions of the eyes are probably distance effects, though there are 

 necessarily a variety of complications. Table 37 shows, however, the 

 extreme need of placing all the radium as nearly as possible on the same 

 spot, the importance of which was not at first adequately appreciated 

 (compare series 2). Radium placed at c produces over eight times as 



