Magnetic Charge as a ``Hidden'' Gauge Symmetry

A theory containing both electric and magnetic charges is formulated using two vector potentials, $A_{\mu}$ and $C_{\mu}$. This has the aesthetic advantage of treating electric and magnetic charges both as gauge charges, but it has the experimental disadvantage of introducing a second massless gauge boson (the ``magnetic'' photon) which is not observed. This problem is dealt with by using the Higgs mechanism to give a mass to one of the gauge bosons while the other remains massless. This effectively ``hides'' the magnetic charge, and the symmetry associated with it, when one is at an energy scale far enough removed from the scale of the symmetry breaking.