﻿Spectrum of Palladium. 155 



brought together in greater groups of lines in conformity 

 with what I have found in several other spectra *.. 



In fact a line has been omitted by Kayser, so that his 

 difference 3968 is the sum of two differences with the values 

 1628 and 2340. The first of these I have already given in 

 my thesis above referred to. Thus, the complete group con- 

 tains 4 lines. It seems, however, as if one line more should 

 be included. This appears only three times, but it follows 

 from its intensity and general appearance, that it belongs to 

 the same group. 



In the table below are given certain wave-numbers "f of 

 lines in the Pd-spectrum, which are arranged in such a 

 way that lines belonging to two corresponding columns 

 A-D in all the rows (1-21) show the same differences. 

 These differences are given in the columns headed A l5 A 2 , 

 and A 8 . In the last of these columns, A 3 , the difference 

 7757 has also been inserted in brackets. The wave- 

 numbers of the corresponding lines (E) are placed in 

 column D. Lastly, the mean of each difference is given 

 at the foot of the table. 



The wave-numbers of the lines in succeeding columns in 

 the table above are given by the relations : 



B=A + 1628*33 

 0=A+ 3968-00 

 D=A + 5159-14 

 (E = A + 11725-45). 



It will be noticed that, excepting the lines 3404 (10R), 

 3380 (5u), 3142 (6), 2763 (8R), and 2441 (6R), all strong 

 lines for the interval 4213 to the end of the spectrum are 

 embodied in the above mentioned system. Among the lines 

 with larger wave-lengths it gives, indeed, many with stronger 

 intensities which cannot be placed in the system. 



We will next consider how these lines, without doubt 

 standing in a certain connexion to one another, are divided 

 in the electromagnetic field. The separation of the lines is 

 indeed very different in the same group as well as by passing 

 from one group to another and does not indicate any simple 

 relation between the lines, for instance that the groups 

 should be produced by the same electron. 



* - l On the Spectrum of Yttrium,"' beiii£ printed in the Astrophvs. J. ; 

 u Kin System von Wellenzahlen im Scandiumspektrum," Phys. Zcitschr. 

 1914, p. 892; " Gesetzmassig-keiten im Ban des Lanthanspektrums," 

 Ann. d. Physik, xlv. p. 1203 (1914). 



t The measurements of the wave- lengths are taken From Kavser, 



