and the Theory of Atomic Structure. 1087 



by some measurements in the K-series. As is seen from 

 diagram I. the following relation must hold for the fre- 

 quencies : 



Table VI. gives some numerical values. 

 Table VI. 



Cd 



LT3-L&- 



K/3S-K&. 



40-41 

 35-44 

 3297 

 26-70 



39-0 

 32-4 

 34-7 

 26-5 



Pel 



Eh 



Mo 





The values for the K-lines of Eh and Mo are calculated 

 from the wave-lengths given by Duane * (K/5 2 is called K/y 

 hy Duane). The values for Cd and Pd have been kindly 

 furnished me by Mr. A. B. Leide, who has measured some 

 K-lines in this laboratory. As an error of 0*5 X.U. in one 

 of the K-lines involves an error of more than 4 per cent, in 

 the differences under consideration, we may say that the 

 agreement is very good. 



The line /3 6 crosses /3 4 and /3 3 twice, a circumstance which 

 in the beginning gave rise to some difficulties in the identi- 

 fication of these lines. /3 6 crosses /3 4 once for Pt and /3 3 for 

 Dy and crosses both lines again between Hh and Mo. In 

 this region the y3 6 -curve is nearly a straight line in the 

 Moseley-diagram, whereas the /3 3 - and /3 4 -lines are noticeably 

 curved. 



§ 6. As regards the intensities of the different lines, it 

 has been found that for the elements U-W the lines /3 3 and 

 /3 4 are not much different in intensity, but in the region 

 Ba-Rb /3 3 is much more intense than /3 4 . An illustration of 

 this fact is given by figs. 1 and 2 (PL XXIII.) f- Fig- 1 gives 



* Phys. Review, II. xiv. p. 373 (1919). 



t The reproductions are about twice the natural size. The black 

 lines in the original photographs are represented as white lines in the 

 reproductions. 



