  The purpose of the study is to further investigate the classical Gibbs
analysis of the heterogeneous system "stressed crystal - melt." It is
demonstrated that each equilibrium configuration is stable with respect to a
special class of variations introduced by Gibbs. This basic result is compared
with the opposite result on the universal morphological instability of phase
interface separating a stressed crystal with its melt. Some plausible
manifestations of the instabilities implied by the Gibbs model are
qualitatively discussed.
