energy had aceummlated on the side of the infinitely small wave-lengths. 
It is clear that here too theory is in direct contradiction with 
experience. Still it is easy to see that we must come to this conclusion 
if we assume the three following suppositions : 
Oe Oh . 
A. The relation %~ “* =O is satisfied. Here n represents the 
dome cl 
total number of independent variables, p, an arbitrary of these variables. 
In mechanies both the generalized coordinates and their time varia- 
tions or the corresponding momenta are to be considered as independent, 
so that in a mechanic system m represents twice the number of 
degrees of freedom. 
B. There is statistical equilibrium. 
C. All the phases (in the sense of GrBBs) representing the same 
energy, lie on the same path. 
By Jpans') and by W. Rrrz’) attempts have been made to explain 
this contradiction between theory and observation. In a certain sense 
also by M. Pranck, though the latter does not start from Grpps’s 
statistical method in his theory of radiation. As none of these theories 
satisfies me entirely, I shall state here another direction in which 
a solution of the contradiction might be sought. Before proceeding 
to this, however, I consider it my duty-to indicate why the three 
theories mentioned do not satisfy me, as else 1 should not be justified 
in adding another view to the number of existing ones. 
On a superficial consideration Rrrz’s theory makes the impression 
to look for the solution of the difficulty in this that it rejects suppo- 
sition C. For Ritz wants to reject a great number of states of the 
electromagnetic field which are compatible with the field equations, 
because in his opinion they cannot occur. Thus he assumes only 
waves originating from electrons, not such ones as converge on them, 
because, if the latter existed, the electron would be a perpetuum 
mobile. From these words it appears already that it is really suppo- 
sition B that is rejected by Ritz. The system he considers, constantly 
loses energy, and so it is not, in equilibrium. If we think the material 
universe to oceupy a finite space surrounded by an ether which 
reaches to infinity, it must of course lose energy, and cannot be in 
equilibrium. But then we knew already that on account of the 
prevailing differences of temperature the material universe is not in 
equilibrium. We have always only to deal with limited systems 
which are surrounded by other systems, and which are only for a 
1) Comp. i.a. Le. and Phil. mag. Series VI. Vol. II, p. 638. 
2) Rirz. Phys. Zeitschr. Vol. IX. No. 25 p. 907. Anno 1908, 
