The dependence of the maximal growth rate of the modes of the Rosensweig
instability on the properties of the magnetic fluid and the external magnetic
induction is studied. An expansion and a fit procedure are applied in the
appropriate ranges of the supercritical induction B^. With increasing
B^ the scaling of the maximal growth rate changes from linear to a
combination of linear and square-root-like scaling. The scaling of the
corresponding wave number alternates from quadratic to primarily linear. For
very small B^ the dependence of the maximal growth rate on the viscosity
is given. Suggestions are made for experiments to test the predicted scaling
behaviours.Comment: 8 pages, 4 figures; to appear in Europhys. Let