36 McCieLianb and Hackutt—Secondary Radiation from Compounds. 
atoms ; if they were free electrons just before emission, it is difficult to see how 
such remarkable relations should exist between the atomic weight and the 
intensity of the secondary radiation. 
It may be mentioned in conclusion that the further measurements of this 
secondary radiation treated of in this paper confirm our previous belief as to 
the small difference of atomic weight that can be detected by the corre- 
sponding difference in intensity of the radiation. At a part of the curves (fig. 2) 
where the secondary radiation is increasing most rapidly a difference of one 
unit in atomic weight would readily be detected by the difference in the 
secondary radiation. 
