82 NUCLEATION OF THE UNCONTAMINATED ATMOSPHERE. 



appreciably penetrable even from this remote distance. So far as the 

 data go the absorption is relatively marked between 0.5 and i mm. of 

 thickness, the rates being much larger here than for greater or smaller 

 thicknesses. 



TABLE 51. Penetration of tinned iron plates, 0.05 cm. thick. 

 5^ = 25 cm. Wood fog chamber in lead casket. 



= 6oo cm. 



* Second exhaustion made, but not recorded. Usually ^3= 



. 



<5cd>. 27. Radium . Mttrp. m wad . Jican dafo. 



2. 3 



FIGS. 83-87. Illustrating tables 47, 51, 53, 54. 



