The Chemistry of Colloids. Part I., Kolloidchemie, by Richard Zsigmondy. Translated by E. B. Spear, Associate Professor of Inorganic Chemistry, Massachusetts Institute of Technology. Part II. Industrial Colloidal Chemistry, by E. B. Spear. A Chapter on Colloidal Chemistry and Sanitation, by J. F. Norton, Assistant Professor of Chemistry of Sanitation, Massachusetts Institute of Technology. (New York: John Wiley and Sons, Inc. London: Chapman and Hall, Ltd. 1917.) Price: 13s. 6d. net.