PAINTING MATERIALS Short Encyclopaedia BY RUTHERFORD J. GETTENS Chemist, Department of Conservation, ana Fellow for Technical Research, Fogg Museum of Art AND GEORGE L. STOUT Lecturer on Fine Arts and Head of the Department of Conservation, Fogg Museum of Art WITH AN INTRODUCTION by EDWARD W. FORBES Director, Fogg Museum of Art FOURTH PRINTING NEW YORK D. VAN NOSTRAND COMPANY, INC 250 FOURTH AVENUE