  In classical continuum mechanics, quasi-linear systems of conservation laws
can be symmetrized if they admit an additional convex conservation law. In
particular, this implies the hyperbolicity of governing equations. For
capillary fluids, the internal energy depends not only on the density but also
on its derivatives with respect to space variables. Consequently, the governing
equations belong to the class of dispersive systems. In that case we propose a
symmetric form of governing equations which is different from the classical
Godunov -Friedrichs - Lax representation. This new symmetric form implies the
stability of constant solutions.
