to an electron, whether free or bound, an intrinsic property of light itself.
Fig. 35—Showing how photo-electric stopping potentials of different metals are compared by rotating
and
in vacuo into the position of
.
But a beautiful discovery by Klein and Rosseland[187] a little later, in Bohr’s Institute, made this conclusion unnecessary. For it showed that there was an intermediate process, namely, a so-called collision of the second kind, by means of which the energy