886 FOODS AND FOOD ADULTERANTS. 
sample by amagnet. It may be distinguished from magnetic iron oxide 
by the separation of metallic copper from cupric salts. 
Magnetic oxide of iron.—Blyth! states that ferruginous particles are 
sometimes found as adulterants of teas. These particles may be sepa- 
rated by a magnet. The author quoted (loc. cit.) states that he has 
found over 1 per ‘cent of this ferruginous sand in teas, and that it must 
have been an adulterant. : 
Sand, particles of brick, ete—A small amount of sand in a tea may 
be due to accidental causes while gathering the leaves, but any consid- 
erable quantity and particles of brick and similar matter can only be 
considered as having been added with fraudulent intent. These sub- 
stances may be separated by shaking the leaves with water and collect- 
ing the sediment. 
Copper.—The green color of some teas is popularly attributed to cop- 
per. There is little evidence to prove that copper has ever been em- 
ployed for this purpose. Hassall? made a large number of examinations 
of teas without detecting copper in a single sample. If copper is pres- 
ent in a tea a portion of the powdered sample added to ammonia water 
will impart a blue tint to the latter, the depth of the tint cepengiie 
upon the amount of copper present, 
LIE TEA. 
This substance, as its name implies, is an imitation of tea, usually 
containing fragments or dust of the genuine leaves, foreign leaves, and 
mineral matters, held together by means of a starch solution and col- 
ored by one of the facing preparations. Itis stated that gunpowder 
and imperial teas are more subject to this form of adulteration. Of the 
samples examined by the Department of Agriculture all were free from 
lie tea. 
According to Hassall? the percentage of ash in lie tea ranges from 
13.05 to 52.92 for black teas and 13.13 to 56.34 for green teas. The 
same authority also found black teas containing from 6 to 17.7 per cent lie 
tea, and green teas containing 1.38 to 48.46 per cent of this adulterant. 
To detect lie tea treat the suspected sample with boiling water; if it - 
contain this adulterant portions will break up into dust and leaf 
fragments. 
GENERAL REMARKS ON TEA ADULTERANTS. 
The adulterants of teas, as a rule, are not such as may be consid- 
- ered prejudicial to the health. The mineral matters employed in fac- 
ing, ete., with the exception of salts of iron or copper, are insoluble in 
water, hence would not be present in the infusion. Copper, which is 
1Foods: Their Composition and Analysis, A. W. Blyth, 322. 
2 Food, Its Adulterations and the Methods for Their Detection, A, H. Hassall, p. 131, 
3 Hassall, op. cit., 117. 
