The Second Gibbs Paradox

In his Equilibrium of Heterogeneous Substances Gibbs seems to suggest that the chemical potential of a crystal nucleus need not be equal to that of the coexisting fluid. In the field, Gibbs's statement has been something of a hot potato. I argue that a consistent treatment of point defects in the critical nucleus is essential for clarifying the meaning of the chemical potential of the nucleus. In the end -- as always -- Gibbs was right.