43 
1920-21.] iEther and the Quantum Theory. 
proved that the classical dynamics cannot explain magnetism. No one, in 
fact, has been able to explain how an electron orbit can be tilted under the 
influence of a magnetic field. 
Sir Alfred Ewing has directed attention recently to the resemblance 
between the form of the curve showing the relation between specific heat 
and temperature deduced from Planck’s theory and that representing the 
magnetisation of a specimen of iron. The resemblance in mathematical 
form between Planck’s equation and that of Langevin for the intensity of 
magnetisation of a paramagnetic gas had previously attracted the attention 
of Benedicks.* These similarities suggest that the same type of action 
underlies the quantum theory as the various physical phenomena here 
referred to. 
All these results seem to be in harmony with the view put forward in 
the present paper, that the “ quantum ” is itself essentially magnetic. It 
must not, however, be supposed that the view “ reconciles ” the quantum 
theory and classical dynamics. My object is rather to seek to understand 
more clearly the nature of the quantum, whilst accepting the conclusion 
that some modification of the old theories is inevitable. 
* Benedicks, Annalend. Physik , vol. xlii, p. 133 (1913). 
(Issued separately January 24, 1921.) 
