  We show that if we consider the full statement of Faraday's law for a closed
physical circuit, the standard Maxwell's equations in the presence of electric
and magnetic charges have to include in their integral form a mixed term of the
form $\rho_m {\bf v}_e^{\perp}$ where $\rho_m$ is the magnetic charge density
and ${\bf v}_e^{\perp}$ the perpendicular component of the velocity ${\bf v}_e$
of the electric charge.
