886 FOODS AND FOOD ADULTEKANTS. 



sample by a magnet. It may be distinguished from magnetic iron oxide 

 by the separation of metallic copper from cupric salts. 



Magnetic oxide of iron. Blyth 1 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, etc. 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 2 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 depending 

 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. It is 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 3 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 portioMS 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, etc., with the exception of salts of iron or copper, are insoluble in 

 water, hence would not be present in the infusion. Copper, which is 



'Foods: Their Composition and Analyst*, A. W. Blyth, ',W2. 



* Food, Its Adulteration!* and the Methods for Their Detection, A. II. Hassall, j. 131, 



a Hassall, vjj. cit., 117. 



