BUCKWHEAT FLOUR TEA 373 



see under Calcium Sulphate on page 338. The presence of an 

 inorganic adulterant would be apparent in flour treated with 

 a solution of iodine where the starch and proteids would be 

 stained and the inorganic matter would be left uncolored. 



Adulterants of Buckwheat Flour. Wheat flour and corn 

 flour. The characteristic starch-grains in each would reveal 

 the presence of the adulterant. 



Adulterants of Jams, Marmalades, and Preserves. Pulp 

 of turnip, beet, apple, figs, pumpkin, and watermelon; starch 

 paste, gelatine, agar-agar, grass seeds to imitate seeds of berries. 

 Adulterants in this class are sometimes very hard to detect, 

 partly because of the materials having been macerated by cook- 

 ing, and partly because of the scarcity of characteristic elements. 

 Pure fruits raw and cooked, of which the jams, etc., are claimed 

 to be made, should be studied under the microscope, and the 

 probable adulterants should be studied in the same way. Employ 

 aniline sulphate and phloroglucin to bring out lignified walls. 

 Dilute some of the suspected product with water, allow it to 

 settle and study the residue under high powers, when the presence 

 of silicious diatom skeletons would indicate the presence of the 

 seaweed agar-agar. 



Adulterants of Canned Tomatoes. Pulp of carrots, tur- 

 nip, sugar beet, coal tar dyes. 



Adulterants of Sweet Chocolate. Wheat flour, corn- 

 starch, peanut meal, peas, acorns, arrowroot, and cocoa shells. 



Adulterants of Tea. Tea is sometimes colored with Prus- 

 sian blue, indigo, turmeric, soapstone and gypsum. Black tea 

 is sometimes coated with plumbago. Under the microscope 

 plumbago can be made out by its shining, glossy appearance, 

 Prussian blue by its transparent, light blue particles, and in- 

 digo by its greenish-blue particles. The color of Prussian blue 

 is removed by sodium hydroxide while that of indigo is not. 



The leaves of the following plants have been used as tea adul- 

 terants: Lithospermum officinale, Epilobium angustifolium, 

 E. hirsutum, Salix sp., Fraxinus sp., Sorbus aucuparia, Morus 

 alba and nigra, Coffea Arabica, Camellia Japonica, Prunus 



