1920. No. 2. ON THE X-RAY SPECTRA. 33 



It appears from the table that the agreement is remarkably good, 

 and in fact the best hitherto obtained. Fig. 4 represents the curves 

 j=:f(N') corresponding to the calculated and observed values. A comp- 

 arison with fig. 2 shows, that the theoretical curve of fig. 4 gives a better 

 agreement than any of those in fig, 2. 



Fig. 4. 



In the case of Lg, the second line of the Z-radiation, we are on 

 less certain ground. 



First of all there may be some doubt as to which of the ^-lines of 

 SiEGBAHN we might take as the one which is produced by recombination 

 from T -- 4 to the circular Z-ring. As before, we take the ß^ line of 

 Siegbahn to be produced by recombination from t = 3 to an elliptic state 

 of the L-ring. But still we shall have the choice between ß.> and ß?^ 

 (Sommerfeld ;' cP). As before we shall consider ß^ as the second L-line 

 and indicate it simply by La. 



Further there may also be some uncertainty with regard to the 

 constitution of the il/-system. In our calculations we suppose one M-nng 

 with 12 electrons. 



The equation of frequency is obtained from the general equation (5) 

 by putting: 



Vid. Selsk. Skrifter. I. M.-N. Kl. 1920. No. 2. • 3 



