The foundation of physical chemistry is built on uniform systems, such as “ideal” gases and “regular” solutions (1). The basic, simple relationships derived from chemical physics are actually quite sufficient for the analysis and prediction of properties of most mixtures (2). The accuracy of predictions, however, depends on the interactions of the basic physicochemical forces. Uniform behavior described by simple physics only becomes complex when there is competition between interacting forces of similar magnitudes (3). Rheological additives, in every case, introduce new forces into a system which counter and, it is hoped, dominate the existing balance.