368 
DR. W. M. HICKS : A CRITICAL STUDY OF SPECTRAL SERIES. 
separation 308'99 corresponds tb the displaced sequent for m = 2. It thus supports 
the explanation adopted for the triplet modification. 
For reference the multiples of the oun giA'ing the satellite separations are collected 
in the following table, where dj, d.^ refer to the first and second line in a satellite set. 
m = 1. 
m = 2. 
n. 
ch. 
d-2, 
n. 
ch. 
d.2. 
3 
‘■-‘2. 
2 
12 
121 
5 
28 
281 
3 
m 
12f 
1 
103 
1031 
4 
m 
16-1 
7 
124 
.5 
261 
26^- 
8 
224f 
225 
6 
37f 
38 
7 
126-1 
126-1 
m = 3. 
8 
219f 
220 
4 
19| 
KrF .—The F lines form parallel series in which the constant separations depend on 
the satellite separations of the D series. In other rvords the limits are the d{l) 
sequents which form the satellites. Now it has l^een shown aljoA-e that the abnormal 
triplet separations which the D series exhibit is probably due to the fact that the d 
sequent for a giA^en satellite triplet is not the same for each of the three lines, but 
that they are subject to a displacement of one or more ouns. For instance where is 
788 in place of 786 (in round numbers) the difference 2 is due to the fact that is 
not equal to di„ but is (di). If the strongest line is to be taken asTiormal, we 
should expect the d^„, or to be normal rather than d^^ as Di„ is always Aveaker 
than the other lines of a triplet satellite. In this case F„(oo) — di„{Si) and the 
F separation = F„ ( oo) —Fj ( co) = (^j) —which is less than the observed satellite 
separation by about 2. As a fact we do find these diminished separations. In 
searching for F lines therefore we haA^e to examine the spectrum for AvaA'e-lengths 
longer than d^^ and showing as multiplets with separations the same as the satellite 
separations or less. In the particular case of Kr these are 100, 105, 133, 213, 307, 
1048, 1860,"^" and we are to expect series which we Avill denote by F„Avith n from 1 to 8. 
From this point of Auew it is unfortunate that allowance has to be made for the rule 
as to the excessNe displacements occurring in the lower orders {m = 2, 3) and that 
a complete multiplet, showing all the above separations, is not to be expected. With 
Dll (1) = 20976-63 and Di ( oo) = 51655-56 + ^, dn = 30678-93 + ^ = Fj ( oo). The 
mantissa of f is in general large, say, be ween '7 and ’99. Consequently the region 
in which F] (2) is to be found is where the waA’e-number is less than 30768—N/(2-99)^ 
* There may, of course, be others depending on D lines other than those considered in the text. 
1 
