UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 1193 
Washington, D. C. 
February 15, 1924 
ESTIMATION OF COLLOIDAL MATERIAL IN SOILS BY ADSORPTION 
By 
P. L. GTLE, in Charge, Soil Chemical Investigations ; H. E. MIDDLETON, Scientist in Soil Physical 
Investigations ; W. 0. ROBiNSON, W. H. FRY, and M. S. ANDERSON, Scientists in 
Soil Laboratory Investigations, Bureau of Soils. 
CONTENTS 
Page 
UtrWctfn 
Colloidal aid oen-eofloidal wfi particle* 
Prerieas methods of esHmatin g nlloidal materia] ii soils 
Adsorption method if estimating rettoidal material iu soils 
Desoiotiaa of method , 
Experimental procedure 
Experimental results 
Causes ef discordant resilts 1< 
Accuracy of the Adsorption method 29 
Proeedore suggested , 32 
Qiaatitjr ef colloidal materia] in soils 33 
Stmaury 38 
Litwahw cited 39 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1924 
