PLATE II. 



Peas and sorghum grown in water extract of soil scraped 

 from the surface of plot CI, which plot was very infertile due 

 to the application of dried blood. The extract contained a 

 large amount of nitrates and soluble manganese. 



Treatment for figs. 1 and 2 : 



(1) Tap water. 



(2) Soil extract untreated. 



(3) Distillate of soil extract. 



(4) Non volatile part of soil extract. 



(5) Soil extract treated with carbon black. 



(6) Soil extract with CaCU to make a N/20 solution. 



(7) Soil extract precipitated with Ca (0H)2. 



(8) Soil extract evaporated, ignited, dissolved in HCl, and 

 neutralized. 



(9) Soil extract. Second leaching. 



