Ihe Intensity of Reflexion of X-Rays by Rock-Salt. 15 



The figures for (Fci + F^a) in the third column have been 

 corrected for the extinction-coefficient. The intensity of 

 reflexion is so weak in the case of the planes with odd 

 indices that the extinction-coefficient is neodioible, and the 

 values for F C i — F^ a need no correction. In the fifth and 

 sixth columns are given the corrected values for Fci 



Fie-. 8. 



U. !0 















\ 













\ 



\ 

 \ 



\ 













1 



\ 

 t 



1 



) 











< 



l\ 











\ 













c 



>--o» N \ 



Q\ 











^ 



<\_ 



^*V. 















X 



V^Cl 











N 



^Na 



0-3 0-4 



Sin e 



The amplitude of the waves diffracted through an angle 26 by the 

 Chlorine and Sodium atoms are expressed in terms of that scattered 

 by a single electron. The wave-length \ of the rays is equal to 

 0616x10-8 cm. * 



and F Na . The angle of 26 through which the rays are 

 diffracted is given in the last column. 



In fig. 8, both the former values, and those corrected for 

 the extinction-coefficient, are shown. The maximum values 

 for F at = would be expected to be 10 for sodium, 18 for 



chlorine, assuming both atoms to be ionizec 



Th 



e ge 



neral 



