fo. DEPARTMENT OF AGRICULTURE, 
DIVISION OF CHEMISTRY. 
BULLETIN No. 18. 
FOODS 
AND 
FOOD ADULTERANTS. 
INVESTIGATIONS MADE UNDER DIRECTION OF 
H. W. WILEY, 
CHIEF CHEMIST, 
PART SEVENTH: 
. TEA, COFFEE, AND COCOA PREPARATIONS. 
BY 
GUILFORD L. SPENCER, Assistant Chemist, 
WITH THE COLLABORATION OF MR, ERVIN E, EWELL,. 
PUBLISHED BY AUTHORITY OF THE SECRETARY OF AGRICULTURE. 
WASHINGTON: 
GOVERNMENT PRINTING OFFICE, 
. 1892, 
