U. S. DEPARTMENT OE AGRICULTURE. 



BUREAU OF CHEMISTRY BULLETIN No. 98. 



H. W. WILEY, Chief. 



BY 



LYMAN F. KEBLER, 



Chief, Drug Laboratory, 

 WITH THE COLLABORATION OF 



EARL T. RAGAN, 



Scientific Assistant. 



WASHINGTON: 



GOVERNMENT PRINTING OFFICE. 

 1906. 



