  It is shown that detecting or setting an upper limit on the scalar
gravitational radiation is a good experimental test of relativistic gravity
theories. The relativistic tensor-field theory of gravitation is revised and it
is demonstrated that the scalar monopole gravitational radiation must be added
to the usual quadrupole radiation. In the case of the binary pulsar PSR 1913+16
it is predicted the existence 0.735 % excess of the gravitational radiation due
to the scalar gravitational waves.
