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



the change can be explained l>y a collateral change of ( - 3) D ( *) for m = 10-12. The scheme is then as 



follows : 



2-828063 (20) + 10 



*\ 



3-829715 (79) -36 

 4-829715 (190) + 9 

 5-829715 (362) + 58 

 6-829715 (626) -580 

 7-829715 (945) -173 

 8-829715 (2300) + 63 

 9-829715 (3200)+ 1373 

 f 10 -8297 (44) -16 

 Collaterals with j 1 1 8297 (57) - 8 

 (-S)D(oo) 1 12-8297 (78) -5 

 [13-8297 (92) + 8 



The arrangement is seen to be exceedingly simple. The value for m = I has been omitted as the 

 evidence seems strong that Mg conforms to the Zn type and has no D(l). If, however, it is retained, it 

 is now 15A 2 below that for m = 2. The values of Ao are so small that Mg can give no positive evidence 

 for any arrangement. This is evidenced by the changed arrangements called for by more accurate values. 

 The measures of FOWLER and REYNOLDS for the D lines are here adduced in order to complete 

 Appendix II. : 



3097-03 3093-09 3091-19 



2851-76 2848-54 2846-88 



2736-63 2733-64 2732-16 



2672-53 2669-66 2668-24 



2632-98 2630-14 2628-73 



2606-73 2603-98 2602-59 



2588-37 2585-63 2584-32 



2575-02 2575-30 2570-96 



2565-00 2562-30 2560-96 



2557-29 2554-70 



2551-22 2548-56 



Note 2, p. 357. The effect of positive collaterals on D ( ex) for m = 5, 6, 7 is to diminish the separations 

 of the triplets, so that from m = 5 onwards they would show diminishing values. It is interesting to note 

 that the observations bear this out. 



Note 3, p. 380. The F series of the alkalies. In K. the denominator 3-007542 has its mantissa 

 1-007542, and this is 14725(250 + ?) above that of K.F. (3), and 5A = 14700. This suggests that if 

 K.F. (3) has a denominator 3 + d, that of F u (2) is 2 + d, and the 1182 -9 (W.N.) is Fi 2 (2) with a satellite 

 difference 28 and 1346-3 is the collateral F n (2) (5A). In Rb 3-001138 has its mantissa 13289(430 + ?) 

 above that of RbF (3) and A = 12935, so that should have a similar arrangement to that in K. and 2156 

 would correspond to F lt (2) (A). 



Note 4, p. 383. CaF (2). The line with wave number 16203-40 is possibly the F n and F 12 combined. 

 If so, FIS is 16202-66 and is -74 behind 16203-40, and the satellite might have displaced the observation 

 towards itself from 16203-66. The actual separation would easily be 1-00 corresponding to a difference 

 2S, a usual F satellite difference. 16024-72 would be 1-06 on the other side and would correspond to a 

 collateral forming on the violet side. 



