Rontgen Radiation and Corpuscular Radiation, 



457 



the scattered radiation appears to be very much softer than 

 the incident radiation. With the evidence at present available 

 it is not easy to decide whether this is due to an admixture 

 of a feeble soft characteristic radiation or to a general 

 softening of the entire beam in the process of scattering. 

 The evidence, however, is much more in favour of the latter 

 than the former. 



When aluminium was used as a tertiary radiator a cor- 

 puscular radiation was always present. It has been shown 

 that the amount of radiation scattered by a given mass of an 

 element increases with the atomic weight of that element. 

 In the case of the corpuscular radiation it will be seen from 

 the second column of Table III. that the relative amounts of 

 corpuscular radiation produced follow a similar law. (The 

 exceptionally high values when silver is used as a tertiary 

 are no doubt partly due to a special corpuscular radiation 

 accompanying the production of the soft characteristic radia- 

 tion of silver.) 



Taken together these facts, though not in themselves con- 

 clusive, appear to suggest that corpuscles are shot out of a 

 substance when it scatters Rontgen radiation, as well as when 

 it emits a characteristic radiation. 



Fig. 5. 



bot 



5-. 



k ^P>^ 



















^ 







50c 









^ 





k 



qoa 



















e 





















200 

















(E)7c for A 



'MM/A//C/M /IS 



"SKTIAffY ffAD/ 



iTortfofiDwtj. 





100 























y 









, 



1 , 1 



I ,. 1 



1 



i 1 in\ 



fe Co Ni co Z,y /7s Ss Sa Afbfiw/kSAi 



The values of k for aluminium and silver are shown 

 graphically in fig. 5. 



