94 PRACTICAL CORN CULTURE 
ADDITIONAL READING 
‘‘Phosphorus Results.’’ By O. 8. Fisher. Illinois State Reg- 
ister. September 20, 1913. 
““The Salvation of Our Soil.’? By B. E. Powell. Successful 
Farming. February, 1913. 
‘‘Frank Mann’s Soil Book.’’ By Frank I. Mann. (Mr. Mann 
is a practical farmer actively engaged in farming.) 
‘‘Results of Scientific Soil Treatment.’’ By Mann and Hop- 
kins. Ill Agri. Ex. Sta., Bulletin 149. 
‘‘The Fertility of the Land.’’ By Isaac Phillips Roberts. 
