70 NUCL.EATION OF THE UNCONTAMINATED ATMOSPHERE. 



nations are a maximum, while the time elapsed after the exposure 

 (4 minutes) is longest. The amplitude of the alternations is in all 

 cases initially about 2.5 : i, but it must be remembered that the 

 coronas are observed after the second exhaustions. The nuclei caught 

 in the first exhaustions may be estimated at 50,000 to 100,000. 



TABLE 42. Secondary generation. 



* Fails. 



TABLE 43. Continuation of the preceding. Secondary generation. D, distance of 

 X-ray plate (anticathode) of bulb from end of fog chamber. 



