1920. No. 2. ON THE X-RAY SPECTRA. 21 



This formula is almost identical with the one developed in Paper I. 

 on the assumption of recombination from secondaries; but in that case 

 the /.-system was supposed to consists of two rings. 



It appears from the treatment of the .]/-line, that quite a number of 

 assumptions with regard to the composition of the ring systems lead 

 to a fairly good agreement with observations. 



If we assume only one ring with quant number 3 the number of 

 electrons in this ring comes out fairly definite and equal to 12. On the 

 assumption of two 3/ rings there are a number of possibilities, of which 

 the one making <j., = 8 probably is the best one. 



e. The Ä'^-line. 

 § 9- 

 From the point of view here adopted Kß should be produced by 

 recombination from the M-r'ing to the Ä^-ring. 



In the case of the J/-ring we have treated two possibilities, and for 

 Kg we shall also consider the two combinations: 



(].^ = 12 (only one 3/-ring) 

 ryg = 8 (two J/-rings). 



The frequency is found from equations (5^) and (5^), 

 by putting ? = i, A- = 3, h^ i, )?2 = 2, »3 = 3, 



fji = 3, 72 = 7 and 7;j =12 or 8, and: 



(i) ^ 9 ^' - 3>9i I iN^ + 1 1,0 + €Kß i'h = 12) 



(20 a) 

 (20b) 



We need not, however, calculate the frequencies from these formulae 

 for as we have seen previously, the following relation is identically 

 fulfilled : 



Here only |~ j will change with 73, and ( ' J is easily found from 

 the results for K„ and /.„. 



