  In previous papers, we have presented hyperbolic governing equations and jump
conditions for barotropic fluid mixtures. Now we extend our results to the most
general case of two-fluid conservative mixtures taking into account the
entropies of components. We obtain governing equations for each component of
the medium. This is not a system of conservation laws. Nevertheless, using
Hamilton's principle we are able to obtain a complete set of Rankine-Hugoniot
conditions. In particular, for the gas dynamics they coincide with classical
jump conditions of conservation of momentum and energy. For the two-fluid case,
the jump relations do not involve the conservation of the total momentum and
the total energy.
