1920. No. 2. ON THE X-RAY SPECTRA. 37 



To get approximate values of tl we may put ]' = Vq then in these 

 case of K^, Kß, L« we get: 



d = 0,066 A' + 0,53. 



Although the diviation d has the right sign and the right type of 

 variation with N, its absolute magnitude's by far too small to account for 

 the observed deviations from Kossel's relation. 



The Frequency of the Absorption Edges. 



3- 



We assume that the necessary condition for asorption to take place 

 is that the energy quantum /t v of the incident ray is equal to or greater 

 than the energy, which is required to remove an electron from its place 

 in the atom and bring it to an infinite distance with a velocity equal 

 to zero. Let this energy be J E, then : 



h v^ J E 



or if v^ is the frequence of the absorption edge: 



h v^ = JE. 



Assuming that during the removal the angular momentum of the remaining 

 electrons is kept unaltered, we found that the expulsion of an electron 

 from a ring system would be accompanied with a change of energy of 

 all electronic systems outside the broken one. 



We mentioned the possibility that the change of energy escaped in 

 the form of radiation ; but it is perhaps more likely that it is spent on 

 the escaping electron. 



This latter assumption would mean that each electron left behind 

 in the rings at any moment during the time of escape keeps its angular 

 momentum unaltered, and this tendency to keep a constant momentum 

 is eqvivalent to a force which is excerted on the escaping electron, and 

 which on an average is directed away from the nucleus. 



If, however, no energy is wasted by radiatien during the escape of 

 the electron, tlie energy necessary to remove thp electron to infinity, must 

 be equal to the energy, ivhich must radiate out when the electron re- 

 combines from infinity to its original position. 



