( 4B8 ) 



SECOND ASSOCIATKÜ SEUIES. 



Tlie capitals after the wavelengths denote the observers: L. D. 

 LivEiNG and Dewar ; S. Saunders and E. H. Exner and Haschek. 

 Where no further indication is given, the observation has been made 

 by Kayser and Runge. 



Natrium. 



Principal series (the lines of the donblets with greatest X) 

 A = 41447,09 ; a = 1,147615 ; /> = - 0,031484 

 Principal series (lines of the doublets with smallest X) 



A = 41445,20 ; a = 1,148883 ; /; = — 0,031908. 

 For the calculation of the limit of the associated series Rydberg- 

 Schuster's law has been used. With a view to the constant differences 

 of wave frequencies of the doublets of the associated series, I have 

 only carried out the calculation for the components with small 

 wavelength. 



For the l«t ass. series A = 24491,1 ; a = 1,98259^ b = -\- 0,00639 

 For the 2"'i ass. series A = 24491,1; ./ = 1,65160; /> = — 0,01056 



