272 Dr. L. Vegard on the X-Ray Spectra 



Table XIX. 



N. 



vx 



-R cal.. 



v x 



R obs. 



D. 



P. 



Fe26 



513-4 



518-0 



4-6 



0-88 



Ni28 



605-1 



606-7 



1-6 



0-26 



We see from the table that the agreement between 

 observed and calculated values is remarkably good, the 

 difference between observed and calculated values being 

 less than 1 per cent. 



I think this fact strongly supports the correctness of our 

 formula and the assumption on which our theory of X-ray 

 spectra is founded. 



I also think that the absorption edges may give us some 

 valuable information with regard to the constitution of the 

 surface ring and those rings nearest to it. 



Discussion of the Results. 

 § 16. In the preceding part of this paper we have dis- 

 cussed the various possibilities with regard to the process of 

 recombination. The various possibilities treated will be seen 

 from the following scheme : — 



I. Recombination between primaries : 

 a. Conservation of momentum. 

 h. „ energy. 



II. Recombination from a disturbed primary : 



a. Conservation of momentum. 



b. „ energy. 

 III. Recombination from secondaries : 



a. Conservation of momentum ; 



b. „ energy. 



c. Debye's hypothesis. 



The assumption I. b does not lead to any satisfactory 

 result. Although we were able io get a fairly good 

 formula for the K line, the assumption does not seem to 

 give room for further extensions to the other X-ray series. 

 Thus we cannot explain L a by means of the electronic rings 

 which were given through the calculation of K a . For the 

 same reason assumption II. b must be abandoned. In the 

 case of recombination from secondaries the difference between 

 III. a, III. b, and III. c would not come in so long as we only 

 treat the principal (a) line of each series. Rut the difference 

 is very marked indeed when we are considering the (/5) lines 

 and we find that the hypothesis III. a gives by far the better 

 agreement for these lines. 



