  We analyze forward Compton scattering, using real analytic amplitudes. By
fitting the total \gamma p scattering cross section data in the high energy
region 5 GeV < \sqrt s < 20 GeV, using a cross section rising as \ln^2 s, we
calculate \rho_{\gamma p}, the ratio of the real to the imaginary portion of
the the forward Compton scattering amplitude, and compare this to \rho_{nn},
the ratio of the even portions of the pp and p-bar p forward scattering
amplitudes. We find that the two \rho-values are, within errors, the same in
the c.m.s. energy region 5 GeV < \sqrt s < 200 GeV, as predicted by a
factorization theorem of Block and Kadailov.
