487 
As s is small as compared to w, we may develop according to 
powers of —; this gives, when s*,... is neglected: 
Ww 
5 4a Ne? 6 2 / 4 5 
n?—|— = = = — + 87 | —————_ _— + 
3m ye A Ha HNE (n,?—w?’)? | 
24 
24 wo - 2 | ae 
(n 7 qy?)? n,! 3 
Hydrogen. 
From eqq. (II) and (III) we get: 
. n° = 1.4522 w’; n,* = 0.3096 w’. 
hence : 
2a Ne? s 
n—1 =| 19.73 + 280.4 — 
sm w? ow” 
If we introduce the values: 
LE See MET ROE 4.78 X 10-10 
me — ees Y} vs = 4.715 “10; 
22400.” m #e : x 
i= GAN AE 107: 
formula (3) in conneetion with 
h 
mw = af 
2 
gives 
@ == 4.856 X 1015; 
further: 
2s Ne 4 
———— = 1.461 « 1028 
sm 
Thus the dispersion formula becomes: 
dt ae OG AN A Vor as eaters) 
Depise’s formula: *) : 
27¢N e* f “ s° 
n—_l =——_| 19.26 + 75.3 — 
Su” ( 5) 
gives with the same values: 
n—1 = 1.193 & 10-4 + 1,98 X 10-37. 8%. 
The experimental formulae are (cf. Desir, Le. pag. 20, 22), that 
of J. Kocu: 
n—l1 = 1.361 « 10-4 + 2.908 X 10-87 s, 3 
and that of C. and M. Curuperrrson : 
n—1 = 1.362 X 10-4 + 2.780 < 10-37.5%. 
In formula (25) the coefficient of s* appears to be much too large. 
Partly this is due to the frequency n, of the 3-vibration, which is 
smaller than the value of the corresponding frequency in Dxpin’s 
De. p. 20. 
