5 



f\l^ 



MAIN imRARY AGRIC. DEPT. 



COPTRIQHT, 1916 

 BY 



The Association of Official Aqeicui-tural Chemists 



COMPOSED AND PRINTED ATTHK 



WAVERLY PRESS 



Bt THB WiLIJAMS & WiLKINS COMPAHT 



Baltimore, Md., U. 8 A. 



