There is no dearth of experimental evidence to indicate that real space-time is a four-dimensional manifold. At present there is much less certainty in attributing dimensions to the charge space of heavy particles, and it may be worth while to review various hypotheses and the meager experimental evidence in this regard. The Clebsch-Gordon coefficients for /-spin that appear in the =-N (nucleon) scattering resonance imply at least a two-dimensional space for unitary transformations (~), which are conveniently represented in the usual terms of rotations in a three-dimensional space. The apparent symmetry between E and N can be emphasized to the maximum extent by regarding the charge displacement number a = q I z of heavy particles as the third component of another vector A in charge space (~). If A is to be independent of / , there must be added an independent pair of coordinates for the unitary transformations