[ U4 ] 



XVIII. The Ordinals of the Elements and the High-frequency 

 Spectra. By J. R. Rydberg, Professor of Physics at the 

 University of Lund*. 



AFTER having made use of integers of a similar kind 

 already in the year 1885 f in trying to find out the 

 laws of the atomic weights, in .1896 J I expressly emphasized 

 the great importance, or rather the necessity, of introducing 

 ior the qualities of the elements a true independent variable 

 instead of the atomic weight, which no doubt is not a simple 

 quality but of a most complex nature. As such an inde- 

 pendent variable I proposed the ordincds of the elements 

 supposing, after the simple rule for the atomic weights of 

 the first elements from He to CI, that He had the number 2 

 and CI the number 17. Finally, having found in 1913 that 

 the system of the elements did not consist of any periods in 

 an ordinary sense, but of quadratic groups of 4-p 2 elements § 

 (p being the number of the group), I did not doubt that the 

 new numbers (which in the beginning of the series from He 

 onwards were 2 units greater than the old ones) must be the 

 true ordinals of the elements, and therefore ventured to 

 propose that they should be used as rational designations 

 besides the ordinary, as for instance Al (15), Co (29), Ni (30), 

 Ag (49), La (59), Ta (75), Au (81), U (94). 



Now for me it has been of the utmost interest to see that 

 Mr. Moseley, in his excellent researches on the high-frequency 

 spectra ||, has found a simple relation between some of the 

 lines of these spectra and the ordinals of the elements. But 

 as there is a certain difference between my ordinals and Mr. 

 Moseley's numbers, I have allowed myself to calculate his 

 series of lines more completely and in a somewhat different 

 way. 



As we see from the publications quoted, Mr. Moseley in 

 the examined spectra has distinguished several kinds of lines, 

 and of these he has published the wave-lengths of six sepa- 

 rate series which, referring to Barkla and Moseley, we will, 

 for the present, designate as K«, K/3, La, L/3, L<£, and L7. 



* Communicated by the Author. 



t " Die Gesetze der Atomgewichtszahlen," Bihang till Sv. Vetensk.- 

 Akad. Htmdl. xi. No. 13 (1886). 



X " Studien liber die Atomgewichtszahlen," Zeitschr. fur anorg. Chemie, 

 xiv. p. 66 (1897). 



§ " Untersuchungen liber das System der Grundstoffe/' Ltinds Univ.. 

 Arsskrift, N. F. Afd. 2, Bd. ix. Nr. 18 (1913). 



II Phil. Mag. xxvi. p. 1024 ; xxvii. p. 703. 



