In this talk we present a continuum theory for the mutual interaction between mechanics and chemistry in a body composed of two components, one solid and one fluid. The basic tenet here is the conceptual view of this body as a platform for two interdependent phenomena: a macroscopic (mechanical) phenomenon due to the deformation of the solid,, and a microscopic (chemical) phenomenon due to the migration of the fluid through the solid. We also present a specialization of the theory which leads to the classical theory of polymeric gels. This specialization is used to investigate the interplay between mechanics and chemistry in the instability underlying cavitation. advection-reaction-diffusion equation, a problem that is ill-posed. In this