﻿and the Theory of Atomic Structure. 567 



identical with the line denoted by Hjalmar as /3 3 for the 

 elements Mg-S, as has been supposed by Sommerfeld *. 



Anomalies in the region of the platinum group, which we 

 might expect for the lines L/3 5 , L7 6 , Ly^ and perhaps also 

 for the line L/3 7 , have as yet not been established. Only the 

 line L/3 7 seems to be a double line in this region. As, how- 

 ever, for the corresponding line L/3 6 in the region of the 

 rare-earth metals no anomalies were observed, it is hardly 

 probable that this structure of /3 7 should be connected with 

 the development of the O-shell. 



§ 6. As has been stated at the end of Part III., most of 

 the non-diagram lines lie on the short wave-length side of an 

 intense diagram line, their frequency difference with this 

 line being approximately proportional to the atomic number. 

 Moreover, it was suggested that these lines might be emitted 

 by an atom which had lost more than one electron. 



In the meantime, a very interesting paper has been pub- 

 lished by Mr. Wentzel f, in which he treats the non-diagram 

 lines of the X-ray spectrum. In this paper Mr. Wentzel 

 was able to show that the lines measured by Hjalmar on the 

 short wave-length side of the Ka 2 line for the lightest ele- 

 ments are emitted by atoms which have lost more than one 

 electron, and he could account in a very suggestive way for 

 the simple numerical relations which hold for the frequencies 

 of these satellites, and for the order of magnitude of the 

 frequency differences of the satellites and the diagram-lines 

 with which they are connected. 



In the further elaboration of his theory, however, and 

 especially in the part of his paper dealing with the fine 

 structure of the absorption discontinuities, Mr. Wentzel has 

 made some assumptions which seem to be rather unsatisfac- 

 tory from a theoretical point of view $. In Part III. § 9 of 

 this paper I suggested that under certain conditions the 

 atom might lose more than one electron at the same time by 

 an impact with one single high-speed /3-particle, and that the 

 regeneration of such an atom should be accompanied by the 

 emission of a line, which should lie at the short wave-length 

 side of an ordinary diagram-line. Mr. Wentzel, however, 

 supposes that the electrons of double or threefold " ionized " 

 atoms have been removed one by one, thus assuming that the 

 atom, which has already lost one or more electrons, remains 



* Sommerfeld, Zeitschrift f, Physik, v. p. 1 (1921). 

 t Annalen d. Physik, 1. c. 



X Mr. Rosseland, who first called my attention to this fact, will soon 

 give a theoretical discussion of the problem. 



