  The Bekenstein-Hawking ``entropy'' of a Kerr-Newman dilaton black hole is
computed in a perturbative expansion in the charge-to-mass ratio. The most
probable configuration for a gas of such black holes is analyzed in the
microcanonical formalism and it is argued that it does not satisfy the
equipartition principle but a bootstrap condition. It is also suggested that
the present results are further support for an interpretation of black holes as
excitations of extended objects.
