and
. Using the relation
, we get
We see that the total energy of the new configuration is greater than in the original. According to the condition of stability in [§1] the system is consequently stable for the displacement considered. In this connexion, it may be remarked that in [Part I.] we have assumed that the frequency of radiation emitted or absorbed by the systems cannot be determined from the frequencies of vibration of the electrons, in the plane of the orbits, calculated by help of the ordinary mechanics. We have, on the contrary, assumed that the frequency of the radiation is determined by the condition
, where
