X-Rays and the Atomic Weight of Nickel. 



415 



It was evident, however, that the deviation from the normal 

 absorption exhibited when the radiators and absorbers had 



Fig:. 4. 



7009 



55 60 65 



Atomic PV£/cht or ff/io/ATOft 



the same or neighbouring atomic weights, could be best 

 studied by examining the absorption of the radiation from a 

 certain substance by different elements and observing the 

 relation between atomic weight of absorber and the absorption 

 produced. 



In a paper by Benoisfc on the absorption of Rontgen rays, 

 the connexion between the transparency (as measured by 

 the mass of a prism of unit cross-section of an absorbing 

 substance which produces a given absorption of an #-ray 

 beam) and the atomic weight of the absorbing substance, is 

 shown by a curve similar to that shown by the discontinuous 



2 F 2 



