i68
THE QUANTUM [ xn . 5
should be noticed that on these assumptions the size of a negative
electron does not differ from the size of a positive electron, the
radius being a quantity of the same order of magnitude as the
estimate of the radius of an atomic nucleus obtained by Rutherford
from experiments on the scattering of a particles. The radius
of the negative electron on the classical theory is well known
to be a quantity larger than this, but that estimate is derived
from the assumption that the electron may be treated as a
charged sphere.
Although no quantitative explanation has yet been found
for the frequencies v r and v 8 , which have been assigned so as to
give the masses actually observed, it may be suggested that they
are in some way determined by the limiting condition that the
velocity of the extreme edge of the rotating tube cannot exceed
the velocity of light.
It is interesting to compare with the suggestions here made
a surmise as to the relation between positive and negative
electricity put forward independently by Sir Oliver Lodge in
his Presidential Address to the Röntgen Society on November 6,
1923.
“ Let us suppose then that round the nucleus of an atom the
aether is in a state of violent rotation. It might even be suggested
that a proton itself is always and constitutionally in a state of
circulation at a speed comparable to the velocity of light, and
that in this way its mass is accounted for, as distinguished from
the much smaller mass of the electron, which presumably is not
in a state of rotation. We might go so far as to surmise—as
indeed we do for many other reasons, connected with the trans
mission of waves by a vortex filled medium—that the normal
aether contains a constitutional rotation comparable to the
velocity of light, and that upon this, when a pair of electric
units are being somehow generated, two equal opposite rotations
are superposed ; one in opposition to the original rotation, giving
a net result zero ; the other in the same direction, giving a result
slightly nearer to the velocity of light than before, conceivably
sufficient to cause what would otherwise be the mirror-image
of the negative electron to have a mass 1,850 times as big.”
5. Discussion of the Electronic Models
The fundamental electric charge here postulated possesses
axial and not spherical symmetry. Further, it exhibits magnetic
as well as electric properties. It is indeed a “ magneton ” which
serves also as an “ electron.” The spinning electron (Chapter
XVI) employed by Goudsmit and Uhlenbeck may be regarded