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



this paper that if we would stick to the hypothesis of recom- 

 bination between primaries the assumption of one M-ring 

 with 12 or 13 electrons has to be abandoned. 



This is no longer necessary when we assume recombination 

 from secondaries ; because in that case there is always one and 

 only one electron in the system of departure. 



As the simplest hypothesis we shall assume one, M-ring, 

 and calculate the frequency for M a on the assumption of 

 ?3 = 12. 



The values of B and C are found from (5 c) by putting : 



i=3, £ = 4, w 3 =3, y/ 4 = T = 4, p 3 = 10, ^4 = 10 + ^3 



B=s2 p(y io _i^pi] =2 . 093fe==12) . 



W10, q z ) fr(10+g,, l)-2(10 + g 8 -Q-5 ) 



= 17-8(^=12). 



C- 



Further : 



«= 1-3-25 10- { 12 (^25) 4 -11 (^i?y 



/N-21\M 



In Table XV. are given calculated and observed values of 



~ for some atomic numbers. 

 rX 



Table XV. (M a ). 



N. 



(»/»U 



w»w 



P. 



79 



156-4 



156-1 



+0-02 



82 



174-2 



171-8 



+ 1-2 



00 



225-3 



220-2 



+2-3 



92 



2392 



233-4 



4-2-5 



The agreement is seen to be very satisfactory. It should 

 be remarked that if ice give up the assumptions of two L-rings 

 the results given in the table would also have jollowed as a 

 consequence of the assumption of recombination from secon- 

 daries in the original form of this hypothesis. 



Quite generally we might say that if we stick to the 

 hypothesis that that there is only one system with a given 

 quant-number., the modified form of the hypothesis of re- 

 combination from secondaries will give, for the a-line of 

 each series, the same frequency as it did in its original 



