﻿568 



Mr. D. Coster on the Spectra of X-rays 



in this state long enough to be deprived of one electron 

 more, before its regeneration takes place. 



§ 7. As this point is of fundamental importance for the 

 understanding of the laws which govern the constitution of 

 the atom, I have tried to get some experimental information 

 about this question. Though the experiments have only 

 recently been started, the results hitherto obtained seem to 

 be inconsistent with the assumption of the successive ioniza- 

 tion of the inner shells of the atom. As has already been 

 pointed out by Mr. Wentzel himself, from his theory we 

 might expect that the intensity of the lines which are emitted 

 by double ionized atoms should increase with the second 

 power of the intensity of the corresponding ordinary diagram- 

 lines. 



In Part II. § 7 the satellites of the lines La x and L& have 

 been discussed. It was shown that for Ag and the elements 

 with lower atomic number, the satellites of «i have a rather 

 complicated structure. This line seems to be accompanied 

 on the short wave-length side by an emission-band and two 

 rather sharp lines. With the new photographic plate I was 

 able recently to establish a third very faint line of still 

 shorter wave-length than the line denoted as a 4 . 



After some preliminary examinations five photographs 

 were taken of the La lines of silver under the same condition 

 as regards position of the crystal, but under the following 

 different conditions : — 





Tension. 



Current. 



Time of exposure. 



Plate I 



9 mm. spark gap. 



20 m.a. 



3 minutes. 



«, II 



8000 volts. 



40 „ 



40 



„ III 



8000 „ 



10 „ 



80 



„ IV 



4700 „ 



20 „ 



2^ hours. 



„ V 



9 mm. spark gap. 



20 „ 



1| minutes. 



For the Plates II., III., and IV. the tension was read 

 with a Braun electrometer giving the mean tension on the 

 tube. 



No appreciable difference was found for the Plates I., II., 

 and III. This means that in the case of Plate II., the radia- 

 tion being about 2 times as strong as in the case of Plate III., 

 no variation in the relative intensity of the diagram-lines and 



