  Based on the microscopic Maxwell equations, we develop a method of
description of the electric field in a spontaneously polarized isotropic
nonpolar dielectric. We find the solution for the electric field
$\textbf{E}(\textbf{r})$ for several typical examples. Moreover, we generalize
Helmholtz's formula for the electric force acting on a volume element of a
dielectric with regard for the contribution of the spontaneous polarization.
