^{page 132 note *} “On Models of Ferromagnetic Induction,” Proc. R.S.E., 1922. The structure in question is described in § 30 of his paper, and is depicted in plate ii, fig. 22. It was while I was listening to Sir Alfred Ewing's exposition of his model before the Royal Society of Edinburgh that the ideas which have led to the present paper originated.

^{page 135 note *} The case when the electron approaches with velocity great enough to ionise the atom would correspond in our model to the case when the electron imparts to the magnetic structure so great an angular velocity that the structure explodes under the centrifugal strain.

^{page 136 note *} This seems at any rate to be established as regards the fluorescent radiations of preparations of the sulphides of the alkaline earths. Lenard, Pauli, and others have found that the frequency of the radiations can be altered at will by modifying the dielectric constant of the solvent in a way which conforms exactly to the supposition that the frequency depends on capacity as in a Hertzian oscillator, and the capacity is affected by the dielectric constant just as in a condenser.

^{page 139 note *} As the poles which are at rest at the centre of the structure play no part in the functioning of the model, it is simpler to regard them as non-existent and to assume frankly that magnetic currents can exist in an atom, without laying stress on their realisation by means of bar-magnets.

^{page 140 note *} Cf. Thomson, J. J., Phil. Mag., 37 (1919), p. 434.CrossRefGoogle Scholar