Bulletin No. 18. 



V. P. P.— G8. 



U. S. DEPARTMENT OF ACxRICULTURE. 



DIVISION OF YEGETABLE PHYSIOLOGY AND PATHOLOGY. 



B. T. GALLO^A/AY, CHIEF. 



T H E 



PHYSIOLOGICAL ROLE OF MINERAL NUTRiElTS. 



BY 



OSCAR LOEV^, 



OF TIT?. 



Division of Vegetable Physiology and Pathology. 



WASHINGTON: 



G O NMC R N M E N T PRINTING OFFICE, 

 I 899. 



