On the dynamical nature of the molecular systems which emit spectra of the banded type

1.Summary of Paper .—It is now widely believed, for the reasons recounted in 2 below, that when the spectrum emitted by a luminous body is of the banded type, the small vibrators which give rise to the radiation are the molecules of the substance, as distinguished from atoms or ions. This result is applied in 3, which constitutes the main body of the present paper, in order to suggest a dynamical system which is formed of two members in the same way as a diatomic molecule may be supposed to be formed of two atoms, and which has free periods of vibration related to each other by the same formula as holds in the case of banded spectra. This formula presents a certain peculiarity, in that the frequency of vibration occurs in it linearly; whereas in the equation for determining the free periods of dynamical systems in general, the frequency enters by its square. It is shown that from this peculiarity in the radiation of a molecule, certain inferences may be drawn regarding the dynamical character of the connection between the atoms within the molecule, namely, that the kinetic potential of a molecule consists of the kinetic potential of the atoms, together with certain gyroscopic terms: and it is suggested that the exchanges of heat in chemical reactions are due to the necessity for readjusting this gyroscopic energy when the molecules are altered. In 4 it is shown that a mechanism somewhat modified from that of 3 would emit radiations connected by the same law as that which Balmer found for the hydrogen lines.