Zeeman Effect in Satellites of Mercury Lines. 333 



(iii.) The existence o£ a refractive index for both crystalline 

 and amorphous substances is indicated by the theory. 



(iv.) The correction for the temperature vibrations is cal- 

 culated, 

 (v.) The effect of the several electrons in an atom is calcu- 

 lated, and is seen to account for the phenomenon of 

 " excess radiation " observed in the scattering of 

 X rays by amorphous substances. 



(vi.) The results are compared with the experimental results 

 of Moseley and Darwin on rocksalt, and it appears 

 that the reflexion is so good that the formulae on 

 which (ii.) is based must be inadequate in some parti- 

 culars. The wave scattered by one atom disturbs the 

 vibrations of the others. 



My thanks are due to Prof. Rutherford for his kind 

 interest in this research. Also to Mr. H. G. J. Moseley; 

 several of the questions here considered arose from discus- 

 sions with him. 



XXXV. Anomalous Zeeman Effect in Satellites of Mercury 

 Lines. By H. Nagaoka, Professor of Physics, and 

 T. Tak amine, Postgraduate in Physics, Imperial Uni- 

 versity, Tokyo *. 



[Plate V.] 



TN the present stage of our knowledge of the Zeeman effect, 

 _L investigations as regards the separation of satellites of 

 spectrum lines in a magnetic field are very scanty. Gehreke 

 and v. Baeyer t first measured the effect on the satellite of 

 the green line of mercury in weak magnetic fields ; similar 

 measurements were made by Lunelund J on several satellites 

 of mercury lines, but as the strength of the field was limited 

 to a few thousand gauss, the separation was generally pro- 

 portional to the fields. Gmelin § was the first to notice an 

 anomalous effect in the satellite + 224 of the yellow line 

 5790, in which the separation was proportional to the square 

 of the field ; the observation was afterwards confirmed by 

 Lunelund. This singular case was of special interest, as 

 the principal line to which the said satellite belongs is, 



* Communicated by the Authors. 



t Gehreke and v. Baeyer, Verh. d. DeutscJi. Thus. Ges. viii. p. 399 

 (1906). 



% Lunelund, Ann. d. Phys. xxxiv. p. 505 (1911). 

 § Gmelin, Diss. Tubingen, p. 41 (1909). 



