ORGANIZATION OF THE UNITED STATES DEPARTMENT OF 
AGRICULTURE. 
Secretary of Agriculture Henry C. Wallace. 
Assistant Secretary C. W. Pugsley. 
Director of Scientific Work E. D. Ball. 
Director of Regulatory Work 
Weather Bureau -. . Charles F. Marvin, Chief. 
Bureau of Agricultural Economics Henry C. Taylor, Chief. 
Bureau of Animal Industry John R. Mohler, Chief. 
Bureau of Plant Industry William A. Taylor, Chief 
Forest Service W. B . Greeley, Chief 
Bureau of Chemistry Walter G. Campbell, Acting Chief. 
Bureau of Soils Milton Whitney, Chief. 
Bureau of Entomology L. O. Howard, Chief. 
Bureau of Biological Survey E. W. Nelson, Chief. 
Bureau of Public Roads Thomas H. MacDonald, Chief. 
Fixed Nitrogen Research laboratory F. G. Cottrell, Director. 
Division of Accounts and Disbursements A. Zappone, Chief. 
Division of Publications John L. Cobbs, Jr., Chief. 
Library Claribel R. Barnett, Librarian. 
States Relations Service A. C. True, Director. 
Federal Horticultural Board C. L. Marlatt, Chairman. 
Insecticide and Fungicide Board J. K. Haywood, Chairman. 
Packers and Stockyards Administration 1 Chester Morrill, Assistant to the 
Grain Future Trading Act Administration J Secretary. 
Office of the Solicitor R. W. Williams, Solicitor. 
This bulletin is a contribution from — 
Bureau of Chemistry Walter G. Campbell, Acting Chief. 
Microchemical Laboratory B.J. Howard, in Charge. 
additional copies 
OF THIS PUBLICATION MAY BE PROCURED FROM 
THE SUPERINTENDENT OF DOCUMENTS 
GOVERNMENT PRINTING OFFICE 
WASHINGTON, D. C. 
AT 
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PURCHASER AGREES NOT TO RESELL OR DISTRIBUTE THIS 
COPY FOR PROFIT.— PUB. RES. 57, APPROVED MAY 11, 1923 
A 
