1055 
(3 VAS = m 
Po T= =| ae ae Vase 5 (90,7 + 9,7 + 2,? + 2,7) 
2 ORI al» 2 or ATEN 2 tel a | 12 
= ea ze an Gat 2)" oe 94.3798 re lere) > (3) 
r 3dr? eons 16 327? 8r? 
After introduction of the condition for stationary motion 
h? 8 W3—l1 
—_ = (mr? wo)? = mre? OES ie 
4? 4 
the first power terms have vanished as they ought to. 
Formula (8) shows that the hydrogen molecule of Bour-Drpise 
satisties Bonr's criterion of stability. The question remains in how 
far a system with a limitation of its freedom of motion consisting 
in the constancy 
y of moments of momentum can execute forced 
vibrations under the influence of external forces which without that 
restriction would change those moments. 
§ 6. Finally we may mention some remarks of others on the 
hypotheses of Bonr-DeEBIJP. SOMMERFELD °) has applied to molecules 
of a more complicated structure the method of deduction of the 
dispersion formula used by Dersue.. In his paper he says that Desir 
has shown that the frequencies of the free vibrations of the system 
need not be real. Such a proot however is not to be found in 
Desun’s paper, only a remark about the good agreement between the 
experimental and theoretical dispersion formulae exactly on account 
of the terms that cannot become infinite for real frequencies of the 
transmitted light. 
OspeN®) shows that Maxwerr’s equations cannot hold for the space 
between the atoms and molecules, if we suppose the electrons not to 
radiate and therefore give up the validity of those equations for the 
space within the atom or molecule. However it is on their validity 
that Desie’s deduction rests. 
Krrsom *) has investigated the magnetic properties and has been led to 
the conclusion that with this constitution of the molecules hydrogen would 
be paramagnetic with a susceptibility only little below that of oxygen. 
In conclusion, I should like to express my indebtedness to 
Prof. Lorentz for his interest and many helpful suggestions. 
1) A. Sommerrerp: Die allgemeine Dispersionsformel nach dem Bour’schen 
Modell: Sonderabdruck aus den Arbeiten aus den Gebieten der Physik, Mathematik 
und Chemie J. Erster u. A. Geren gewidmet p. 577. 
2) CG. W. Osren: Das Bour’sche Atommodell und die Maxwrrr’schen Gleichungen 
Phys. Zeitschr. XVI, 1915, p. 395. 
5) W. H. Keesom: The second virial coefficient ete, These Proc. XVIII p. 637, 
note 2, 
