  A generalization of the Van der Waals excluded volume procedure for the
multicomponent hadron gas is proposed. The derivation is based on the grand
canonical partition function for the system of particles of several species
interacting by hard core potentials. The obtained formulae for thermodynamical
quantities are consistent with underlying principles of statistical mechanics
as well as with thermodynamical identities. The model can be applied to the
analysis of experimental data for particle number ratios in relativistic
nucleus-nucleus collisions.
