  A Coulomb gas representation of dense-matter QCD is derived from a dual
transformation of the low-energy effective Lagrangian. The point-like charges
Q=+1,-1 of the gas are identified with the instantons and anti-instantons of
such topological charges. An instanton repels another instanton with the same
force as it attracts an anti-instanton, in contrast to the semiclassical
interaction.
