  We present results of out--of-equilibrium transport measurements made on
strongly-localized Beryllium films and demonstrate that these films exhibit all
the earmarks of intrinsic electron-glasses. These include slow (logarithmic)
relaxation, memory effects, and more importantly, the observation of a memory
dip that has a characteristic width compatible with the carrier-concentration
of beryllium. The latter is an empirical signature of the electron-glass.
Comparing various non-equilibrium attributes of the beryllium films with other
systems that exhibit intrinsic electron-glasses behavior reveals that high
carrier-concentration is their only common feature rather than the specifics of
the disorder that rendered them insulating. It is suggested that this should be
taken as an important hint for any theory that attempts to account for the
surprisingly slow relaxation times observed in these systems.
