-The prediction of interfacial area in agitated dispersions is of considerable importance in heat and mass transfer operations and in certain heterogeneous reactions. Rietema (11) discusses control of reaction rate in a stirred-tank reactor through control of drop size and interfacial area. Interfacial area control also plays an important role in liquid-liquid extraction (15), dispersion polymerization (7, 8), and direct-contact heat transfer (18).When two immiscible liquids are agitated, a dispersion is formed in which continuous breakup and coalescence of drops occurs. After some time a dynamic equilibrium is established between breakup and coalescence and a spectrum of drop sizes results. The average drop size and the size distribution will depend upon conditions of agitation as well as hysical properties of the two liquids. Drops are believex (6) to be broken up by turbulent pressure fluctuations in the neighborhood of the drop surface. Coalescence may occur when drops collide. In a dilute dispersion coalescence will be minimal, and the e uilibrium ess alone.Despite the fact that the drop size distribution is a significant factor apart from its influence on the average particle size and the total interfacial area, no information exists from which one may predict the distribution function, and the manner in which it changes, with agitation parameters and physical properties of the immiscible phases. The goal of this work was to develop such information over a wide range of pertinent parameters and properties and to imbed these results within the framework of a rational theory.A fair1 extensive literature exists with regard to the average irop size obtained in dispersions. A critical discussion of this literature may be found in reference 2. Only the most pertinent references are reviewed here.