Solution
= Solution
A dielectric is a medium whose constituent charges become polarized by an applied <electric field>; it may also acquire a magnetization. Spatial variation of $P$ leaves uncompensated dipole charge, giving $\rho_{\rm bd}=-\nabla\cdot P$. Time-dependent polarization transports charge and aligned microscopic current loops contribute magnetization current, giving the <bound charge and bound current>
$$
J_{\rm bd}=\partial_tP+\nabla\times M.
$$