  In a recent paper [Phys. Rev. E 61, 2831 (2000)], Borstnik, Stark and Zumer
have studied the stability of a colloidal dispersion of micron-sized spherical
particles in the isotropic phase of a nematogenic material. Close to the
nematic transition, the attraction due to a surface-induced paranematic order
can yield flocculation. Their calculation of the nematic-mediated interaction
was based on an ansatz for the order-parameter profile. We compare it with an
exact numerical calculation, showing that their results are qualitatively
correct. Besides, we point out that in the considered regime, the exact
interaction is extremely well approximated by a simple analytical formula which
is asymptotically exact.
