U. S. DEPARTMENT OF AGRICULTURE. 



DIVISION OF CHEMISTRY. 



BULLETIN No. 13. 



FOODS 



AND 



FOOD ADULTERANTS. 



INVESTIGATIONS MADE UNDER DIRECTION Or 



H. W. WILEY, 



CHIEF CHKMIST. 



PART SEVENTH. 



TEA, COFFEE, AND COCOA PREPARATIONS, 



35Y 



GUILFORD L. SPENCER, Assistant Chemist, 



WITH THE COLLABORATION OF MR. ERVIN E. EWELL. 



PUBLISHED BY AUTHORITY OP THE SECRETARY OP AGRICULTURE.. 



WASHINGTON: 



GOVERNMENT PRINTING OFFICE, 

 1892, 



