  We derive constraints on corrections to Newtonian gravity of the Yukawa type
and light elementary particles from two recently performed measurements of the
gradient of the Casimir force. In the first measurement the configuration of
two Au surfaces has been used, whereas in the second a nonmagnetic metal Au
interacted with a magnetic metal Ni. In these configurations one arrives at
different, respectively, similar theoretical predictions for the Casimir force
when the competing theoretical approaches are employed. Nevertheless, we
demonstrate that the constraints following from both experiments are in mutual
agreement and in line with constraints obtained from earlier measurements. This
confirms the reliability of constraints on non-Newtonian gravity obtained from
measurements of the Casimir force.
