  In their recent communication (Phys. Rev. B 64, 060406(R) (2001)) Cornelius
and Gardner have reported the results of magnetization and susceptibility
studies on single crystals of the pyrochlore Ho2Ti2O7. The observed field
dependence of magnetization is totally unexpected, as it seems to suggest that
the magnetic moments in this compound do not obey the 'ice-rule'. We have
re-measured the magnetization curves for Ho2Ti2O7 single crystal for the three
principal directions of an applied magnetic field and found nearly perfect
agreement with the predictions for a nearest-neighbor spin-ice model.
