THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[SIXTH SERIE8.] 



1919ULJY 1919. 







s System in the Spectrum of Gold. 

 By W. M. Hicks, F.R.S.* 



I^HE spectra of the copper group of metals are interesting 

 in that, whilst they offer clear evidence of being built 

 upon the same plan, they seem defective in representatives 

 of the ordinary series lines and in some apparent deviations 

 from relations indicated by other groups. They all show a 

 pair of strong doublets in the ultra violet, a curious set of 

 inverted D lines in the red — proved to belong to the D (or F) 

 system by their Zeeman patterns — linked to associated lines 

 by analogous e and u links, and S (2) doublets in the im- 

 mediate ultra red also proved to belong to the 8 system by 

 their Zeeman patterns. In copper and silver only two or 

 three other lines have been assigned to S and D series, whilst 

 in gold none have been allocated. The present communi- 

 cation attempts to throw some light on the series relations in 

 gold. Although it does not pretend to be a thorough dis- 

 cussion of the material at disposal, certain definite results are 

 arrived at, and some striking illustrations are afforded of 

 general laws obtained in a series of papers published in the 

 4 Transactions of the Royal Society ' t. 



* Communicated b} r the Author. 



t "A Critical Study of Spectral Series," Trans. Roy. Soc. I., 210 A. 

 p. 57 (1910).— II., 212 A. p. 33 (1913).- III., 213 A. p. 323 (1914).— IV., 



217 A. p. 361 (1918) ; and V., read Jan. 23 (1919). References in the 

 present paper are made iu [ J, thus — [IV. p. — ]. 



Phil. Mag. S. 6. Vol. 38. No. 22?>. July 1919. 



B 



