. The value found by Duane’s X-ray method,[158] which is thought to yield a result correct to one part in 700, is exceedingly close to mine, namely,
. Substituting this in (38), we get with the aid of Bucherer’s value of
(
), which is probably correct to 0.1 per cent,
, which agrees within a fourth of 1 per cent with the observed value. This agreement constitutes most extraordinary justification of the theory of non-radiating electronic orbits. It demonstrates that the behavior of the negative electron in the hydrogen atom is at least correctly described by the equation of a circular non-radiating orbit. If this equation can be obtained from some other physical condition than that of an actual orbit, it is obviously incumbent upon those who so hold to show what that condition is. Until this is done, it is justifiable to suppose that the equation of an orbit means an actual orbit.