Official and tentative methods of analysis of the association of official agricultural chemists, 5th Edition, prepared by the Editorial Board, W. W. Skinner, Chairman, Committee on Editing Methods of Analysis, E. M. Bailey, Chairman, L. E. Warren, J. W. Sale, G. G. Frary, H. A. Lepper and Marian E. Lapp. Published by the Association of Official Agricultural Chemists, P. O. Box 540, Benjamin Franklin Station, Washington, D. C. Price $5.00