  Differential cross sections for elastic scattering of photons have been
measured for $^{40}$Ca at energies of 58 and 74 MeV and for $^{16}$O and $^4$He
at 61 MeV, in the angular range from 45$^o$ to 150$^o$. Evidence is obtained
that there are no significant in-medium modifications of the electromagnetic
polarizabilities except for those originating from meson exchange currents.
