  In this paper it is shown that the forces which resist the acceleration of
the mass of the electron, $m_e$, arising from the Compton effect, the
Klein-Nishima-Kann formula for its differential cross section and the
transversal Doppler effect when the electron moves in a straight line coincide,
with $\vare<1,16\times10^{-4}$, with the force required to propel me with the
same acceleration, if the radius of the electron is equal to its classical
radius and if the forces which rise from the interaction of the electron and
zero-point radiation are equal to those deriving from the electrostatic
repulsion of the charge of the electron against itself (Poincare's tensions).
The equations worked in this paper show that there is no difference between
inertial mass and gravitational mass and may be used to determine the value of
the gravitational constant.
