are large in proportion to their difference, will coincide with the frequency of one of the components of the radiation, which according to the ordinary ideas of radiation would be expected from the motion of the atom in these states, provided the last factor on the right-hand side of equation (10) is equal to
. This condition, which is identical to the condition
is in fact fulfilled, if we give to
its value as found from measurements on the hydrogen spectrum, and if for
,
