  We discuss a model with stable topological solitons in Minkowski space with
only three degrees of freedom, the rotational angles of a spatial Dreibein.
This model has four types of solitons differing in two topological quantum
numbers which we identify with electric charge and spin. The vacuum has a
two-dimensional degeneracy leading to two types of massless excitations,
characterised by a topological quantum number which could have a physical
equivalent in the photon number.
