488 
calculation; this makes one of the resonance frequencies lie much 
nearer to the visible spectrum. 
We have found: 
while in the original model : 
n, = 1.4120 
(ef. the paper by Miss H. J. v. Leeuwen. p. 1074). 
Resonance occurs if the incident wave motion has one of the values: 
— 7 B 
s=n, + wo =2.205 w 
$s. n, —w — 0.205 
2 1 
i == a, =— 0.556 w 
2, is the smallest; to it corresponds a wave-length of about 1890 
ed . 
A units). 
Helium. 
For Helium: n,? = 2 w? = 0.7143 ~*, and so n,* — w? < 0. Hence 
in formula (25) the principal terms become negative, and for values 
of s not too high 
n<1. 
This is in contradiction with the experimental valnes. (Cf. C. and 
M. Curupertson, Proc. Roy. Soe. (A) LXXXIV, p. 13). 
SUMMARY. 
1. In continuation of the investigation by Miss H. J. van LEEUWEN 
on the instability of Bonr and Desie’s model of the hydrogen 
molecule, a new hypothesis is examined by which the system may 
be made stable. | 
2. The model made stable in this way gives neither for //,, 
nor for He a dispersion formula which agrees with the formula 
experimentally found. 
Note added in the English translation. 
Since this was written a paper has appeared by C. Davisson 
on the Dispersion of Hydrogen and Helium (Phys. Rev. (22) VIII, 
p. 20, . July 1916). 
Mr. Davisson uses the same method to ensure the stability of the 
model, but he arrives at a somewhat different formula (it seems to 
me that he overlooks the influence of the conditions (10) and (11) 
and of the auxiliary forces Q, and Q, necessitated by them on the 
-vibration). As Mr. Davisson points out himself, his formula too 
gives for both gases results which are in conflict with the experi- 
mental ones. 
