Recent observations by Cooper et al. of the charge distributions in /sup 166/Er and /sup 176/Yb bring to mind an old idea that the ground state of finite nuclear matter may exhibit spatially periodic mass-density and charge-density modulation. A feasible experiment employing a polarized /sup 165/Ho target is proposed. A spatially periodic charge modulation could most easily be detected by Bragg scattering of high-energy electrons.