  I introduce the exact relation between the displacement current $\epsilon_0
\partial \v{E}/\partial t$ and the ordinary current $\v{J}$. I show that
$\epsilon_0 \partial \v{E}/\partial t$ contains a local term determined by the
present values of $\v{J}$ plus a non-local term determined by the retarded
values of $\v{J}$. The non-local term implements quantitatively the suggestion
made by Griffiths and Heald that the displacement current at a point is a
surrogate for ordinary currents at other locations.
