T H E 

 LONDON, tiDIN BURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[SIXTH ^BKIJSS.] 



MARCH 1919. 



XXIII. On the X-Ray Spectra and the Constitution of the 

 Atom. II. By L. Vegard, Dr. Phil., Professor of Physics 

 at the University of Christiania *. 



Introduction. 



§ 1. FN a previous paper | published in the Phil. Mag. 

 JL for April this year, I have tried to explain the 

 X-ray spectra from definite conceptions with regard to the 

 system of electrons which surround the positive nucleus. 



My theory of X-ray spectra was based on the assumption 

 that the quant-number of the electrons surrounding the 

 nucleus is not constant and equal to one (Bohr's hypo- 

 thesis), but increases as we pass outwards from the nucleus — 

 from one ring-system to another. 



With regard to the way in which the X-ray spectra are 

 produced, the following two possibilities were considered:— 



(1) An X-ray line is produced by the recombination of an 



electron from" a "secondary" stability circle of a 

 higher quant-number to the " primary " circle which 

 has lost one electron. 



(2) The X-ray line is produced by the recombination of an 



electron belonging to one of the outer " primary " 

 stability circles to the broken primary system (the 

 one which has lost one electron). 



* Communicated by the Author. Communicated as manuscript to 

 the Kristiania Vid. Selsk. on the 18th of September, 1918. 



t L. Vegard, " The X-Rav Spectra and the Constitution of the 

 Atom," Phil. Mag. xxxv. p. 293 (1918). This paper will be referred to 

 as Paper I. 



Phil. Mag. S. 6. Vol. 37. No. 219. March 1919. S 



