104 Dilute Acids and Pliospliorus Compounds in the Soil 



Table IX. Effect of added substances on the reaction between dilute 



acids and soil ijliosfliorus compounds. 



P2O5 extracted in mgms. per 100 gms. of soil. 



I. Organic substances: phenol, o-cresol, and pyrogallic acid. 



Soil, Hoos 26'. Time = 0. 



Soil Hoos 20. Time^O. 



II. Inorganic substances: potash-alum, AI2O3. 

 Soil, Hoos 2 C. Time = 1 hour. 



1000 c.c. N/10 HNO3, the quantity used in the experiments, is equivalent to I'Tgms. 

 of Al.,03. The extracts made with N/10 HNO3 and AI2O3 were very turbid. 



