  We show the relationship between a fluid of particles having charge and
magnetic moment in $2+1$ dimensional electromagnetism and the Chern-Simons
statistical field. The matter current which is minimally coupled to the
electromagnetic field has two parts: the global electromagnetic current, and
the corresponding topological current. The topological current is associated to
the induced electromagnetic current, via a simple constitutive relation between
charges and magnetic moments. We also study the edge states, when the region
that the currents occupy is bounded.
