  In a recent paper [A. O. Sushkov, S. Eckel and S. K. Lamoreaux, Phys. Rev. A
79, 022118 (2009), arXiv:0810.2756 ] the authors measured the EDM-induced
magnetization M that is given by Eq. (1) in their paper. Such an expression for
M is a consequence of the generally accepted opinion that both dipole moments,
a MDM m and an EDM d, are proportional to the spin S. Recently [T. Ivezic,
Phys. Scr. 81, 025001 (2010)] the Uhlenbeck-Goudsmit hypothesis is generalized
in a Lorentz covariant manner using the four-dimensional (4D) geometric
quantities. From the viewpoint of such formulation there is no EDM-induced
magnetization M; in the 4D spacetime the EDM d^{a} is not proportional to
S^{a}. It is argued that the induced M can come from the direct interaction
between the applied electric field E^{a} and a MDM m^{a}.
