141 
1921-22.] On the Quantum Mechanism in the Atom. 
from the incident light happens to be, at the moment, equal to or greater 
than hv, then the free electron will be sucked through the magnetic wheel 
and will come out on the other side, having abstracted energy of amount 
precisely hv from the wheel. Thus, when the energy absorbed by an atom 
of the metal from the incident light amounts to as much as Ilv, the first 
free electron which presents itself is sucked through the atom and relieves 
the atom of the energy hv. The electron, then, arrives at the inner 
surface of the metal on its way out, with energy hv ; it loses energy Iivq in 
passing through the surface, where Iivq is equal to Richardson’s product 
(f)e in thermionics ; and thus the energy with which an electron escapes 
from a metal illuminated by radiation of frequency v is h{v — Vo). 
{Added May 17, 1922.) 
§ 7. Connection with Bohr’s Theory of Series-Spectra. 
The equations (16), (17), (18), which determine radiation according to 
the present theory, afibrd an explanation of the most perplexing feature 
of Bohr’s theory of series-spectra, namely, the question as to how the 
energy, set free b}^ the fall of an electron from one of Bohr’s outer orbits 
to an inner orbit, is transformed into radiation of frequency v determined 
by the equation U — Ar. We can, in fact, assimilate this part of Bohr’s 
theory to the theory of the present paper in the following way. In 
Bohr’s theory let a negative electron E fall from an orbit of radius a^ 
(position P^) to an orbit of radius (position PQ. Now in the initial state 
of this system, which consists of the electron E at P^ , let us introduce two 
coincident electrons E' and E" at P^,, one positive and one negative, so that 
they annul each other ; and let us replace Bohr’s conception of the fall of 
the electron from E at P^ to E' at Pq , by the conception of the discharge 
of a condenser whose charges are E and E'' ; the discharge annihilates 
E and E”, and so leaves E' surviving alone at the end of the process, and 
is therefore equivalent to Bohr’s notion of a translation of E to the position 
of E'. Now the energy set free by the fall of the electron in Bohr’s 
theory is 
u=lYi _ ^ ) 
2 aA 
which, in conformity with tlie above idea, may be written 
where C denotes the capacity of a condenser formed of two spherical surfaces 
of radii and respectively. This is identical with equation (16) above. 
