About the author RALPH K. ILER is currently a consultant and a member of the Advisory Board of the Journal of Colloid and Interface Science. He received his B.Sc. and Ph.D. degrees in chemical engineering from the University of Toronto, and worked for Canadian Industries, Ltd. in Montreal and the Tire Division of U.S. Rubber Company at Detroit, Michigan. From 1937 to 1974, Dr. Iler conducted research in various capacities for E.I. duPont de Nemours and Company. He is responsible for approximately 100 U.S. patents, and is the author of over 25 scientific publications and The Colloid Chemistry of Silica and Silicates.