BUREAU OF SOILS. 



MILTON WHITNEY, Chief of Bureau. 

 ALBERT G. RICE, Chief Clerk. 



SCIENTIFIC STAFF. 



FRANK K. CAMERON, in charge of Physical and Chemical Investigations. 

 CURTIS F. MARBUT, in charge of Soil Survey. 

 OSWALD SCHREINER, in charge of Fertility Investigations. 

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ADDITIONAL COPIES of this publication 

 Xi- may be procured from the SUPERINTEND- 

 ENT OF DOCUMENTS, Government Printing 

 Office, Washington, D. C., at 5 cents per copy 



