CONSTITUENTS OF TEAS. 887 



probably very rarely present, would be very objectionable even in very 

 small quantities. Sulphate of iron is a powerful astringent. In the 

 small quantities which would be used in increasing the astringency of 

 teas it would possibly not be seriously objectionable. It may also be 

 said of sulphate of iron that this substance was not detected in a very 

 large number of samples examined by Hassall nor in the Department's 

 samples. 



Facing, if excessive, increases the weight of the tea, but there is no 

 evidence of its being prejudicial to the health. 



From these statements we see that the adulterations of teas are in- 

 tended more especially to enhance the value of inferior grades, except 

 in the case of lie tea or the addition of foreign or exhausted leaves. In 

 the latter cases a spurious article, which is not justilied by any quality 

 or principle Avhich it contains, is foisted upon the market. 



The evidence of authorities upon food adulteration con firms the state- 

 ment that the addition of foreign leaves is now but little practiced. 

 The general freedom of the teas of the markets of the United States 

 from adulteration is largely due to the enforcement of the United States 

 tea-adulteration law. Dr. Jesse P. Battershall, 1 under whose direc- 

 tion a very large number of samples of teas were examined in con- 

 nection with this law, notes a very perceptible improvement in the 

 quality of teas imported under its provisions. 



GENERAL STATEMENTS CONCERNING THE CONSTITUENTS OF TEAS. 



The analyses of teas give little or no evidence bearing upon the mar- 

 ket value of this commodity. A tea may be very rich in theine or tan- 

 nin, and yet bring the same price as one poor in these substances. The 

 same may be said in a general way of the other constituents. This is 

 largely due, undoubtedly, to differences in soil, climate, the age of the 

 leaf, and methods of manufacture. The flavor, strength, and appear- 

 ance of a tea in general determine its market value. The flavor is due 

 to the volatile oil developed during the manufacture, the strength to 

 the proportion of tannin, and the appearance of the leaf to its age and 

 the care taken in the rolling and other manipulations. A tea may be 

 deficient in tannin and still bring a high price on account of the delicacy 

 of its flavor, or, by the admixture of leaves rich in tannin, an operation 

 termed blending, its strength may be increased to meet the demands 

 of the market. In genuine unfaced teas the value is usually in a direct 

 ratio with the soluble matter in the ash. According to Geisler, the 

 finer the quality of the tea the more theine, soluble ash, and extractive 

 matter it will contain, though this is not uniformly true. It has been 

 stated that the relatively high price of Indian teas is largely due to 

 their percentage of tannin. This permits the use of a very much smaller 

 quantity of tea in preparing the infusion for the table. The writer found, 



' Food Adulteration and Its Detection, K. & F. Spon, New York, p. 20. 



