466 



DR. W. M. HICKS: A CRITICAL STUDY OF SPECTRAL SERIES. 



consist of two doublet series each "with separation of order 167 and a third singlet 

 series. The two sets of doublet series appear to converge to the same limits, in the 

 same way as the satellites of a D series. The first lines given by him are of the order 

 m = 3, but amongst the B.M.M. as also the MEISSNER lines those for m = 2 are also 

 seen. Further, there appear close strong companions to the second lines of doublets in 

 the first series, and in this they recall the behaviour of the F lines in the alkaline 

 earths* and so suggest that they are really lines of the F type, but belonging to a 

 different f sequence from that discussed above. If so the limit must behave as a 

 displaced value from the 31852. The sets are, in ROWLAND units : 



173 



1-06 



* [III., p. 383, seq.] 



t Lilies used in calculating formulae 



J This line was not included by Rossi. 



