Colloid Science is an ancient art. Unfortunately many scientists still regard it as such~ We hope that this book will dispel all such illusions by providing convincing evidence that a quiet renaissance has occurred. The New Colloid Science is based on rigorous, quantitative theory and works with extremely well de­ fined experimental systems. The former was first made possible by the advent of the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of the stability of lyophobic colloids in 1948. This is based on a consideration of the electrostatic interactions among colloidal par­ ticles bearing fixed charges in a medium containing moving counter­ ions. The Hamiltonian formulation of this model by Weiss, Mock, and Moon herein is a significant development in our theoretical pro­ gress. During about the same period we have advanced experimentally from poorly defined "glue-like" systems to monodisperse colloids, synthesized for the first time in 1955 when J. W. Vanderhoff and E. B. Bradford announced their polystyrene colloids with extremely narrow particle size distributions. Vanderhoff and his coworkers have now set another milestone by fully characterizing the surfaces of these systems, as described in this monograph. The revolution is snowballing. Krieger and his coworkers have shown that the opalescent colors exhibited by "deionized" monodis­ perse latexes are due to Bragg diffraction of these liquid-crystal systems, that they exhibit reversible "melting" and that they may serve as macroscopic models for order-disorder phenomena.