940 
molecule according to Bonr-DeBije and he found a remarkable 
agreement with the value derived from the second virial coefficient 
(Comm. Leiden, Suppl. N°. 39a): 
from the equation of state *) 2,03 « 102 (e. st. e. cm’) 
according to Borr-DrEBuE AO aes 5 
However favourable this result may be for the Bonr-Drgije model, 
still it seems probable that the always increasing objections against 
this model?) will compel us to seek for another. The calculation 
of the quadrupole moment from the equation of state retains 
however its value. Abstracted from the incertainty caused by the 
simplifying assumption on the repulsing forces, it gives namely 
important data which will have to be taken into consideration in 
the construction of the definite model of a molecule. In this sense 
it seemed interesting to calculate the quadrupole moments for other 
gases too. In § 2 this has been done for oxygen and for nitrogen. 
§ 2. In the temperature interval in which the second virial coef- 
ficient has been calculated for quadrupole molecules, we possess the 
data comprised in table I for the second virial coefficients of oxygen 
and nitrogen *). 
The index © indicates here that the volume v in the equation 
of state 
| 
pie aE Wales ese 
ee | 
is expressed in the theoretical normal volume as a unit *). 
These data do not admit a control of the change of B for these 
gases with the temperature compared with that of spherical quadru- 
pole molecules. This would require more values of B espe- 
cially for higher temperatures. Let us assume for the present that 
this is the case for the considered temperature interval ®), then they 
When we attend to the circumstance that the molecules are polarized in 
their mutual electric fields, this value will still undergo a small alteration (comp. 
Comm. N°. 66 especially § 4). 
2) Comp Miss H. J. van Lezuwen, these Proc. Vol. XVIII, N°. 7, p. 1071. J. M. 
BURGERS, these Proc. Vol. XIX, 2. p. 480. A. SoMMERFELD, Atombau und Spektra- 
llinien. Braunschweig 1919, p. 288 and 533. Frl. G. Lasxi, Physik. ZS. 20 (1919), 
p. 550. W. Lenz, Verh. D. physik. Ges. 21 (1919), p. 632. 
3) These numbers are taken from the calculations by Mr. M. Daniers, phil. 
nat. docts, where for the observations of AMAGAT were taken the virial coefficients 
given by KAMERLINGH ONNES in Comm. Leiden N°. 71. 
4) Comp. H. KAMERLINGH Onnes und W. H. Keesom, Die Zustandsgleichung. 
Math Enz. V. 10, Leiden Suppl. N°. 23, Einheiten 0. 
5) For hydrogen deviations occur in the corresponding interval already. 
