912 



FOODS AND FOOD ADULTERANTS. 



According to Hassall, 1 the large size of the cells and the absence of 

 milk vessels distinguish this root from chicory. 



Cereals, leguminous seeds, and acorns. Judging from those investiga- 

 tions the adulteration of coftees in this country with chicory is not as 

 common as with cereals, pease, beans, etc. These latter substances, in 

 general, are detected by the presence of starch and are finally identi- 

 fied by their structures as shown by the microscope. 



The following method of A. H. Allen is probably the best for the 

 detection of starches, chemically, in adulterated coftees : 



Boil a portiou of the powdered sample with water and lilter; cool the. filtrate, 

 acidulate with sulphuric acid; add a strong .solution of permanganate of potassium, 

 small quantities at a time, until the coloring matter of the original extract is dis- 

 charged; test for starch as usual with iodine. 



Starch may be easily detected in the finely powdered sample, mounted 

 in Canada balsam, on examination by the microscope, with polarized 

 light. Starch, when examined as above, shows a dark cross on a white 

 field. 



In Part II of this bulletin (Plates xm to xxvm), a number of 

 starches are illustrated as shown by the microscope with polarized 

 light and plain illumination. In the identification of starches it is well 

 to have a series of freshly-prepared slides of the materials from known 

 sources for purposes of comparison. 



Sufficient of the original structures of the cereals or leguminous 

 seeds will usually remain for their identification with the microscope. 

 In this work it is well to have a series of slides prepared from the raw 

 and roasted materials for comparison. 



The following statement of the percentage of ash in cereals is given 

 for comparison with that of coftees. The mean ash of the cereals given 

 is considerably lower than that of coft'ee. 



Ash' 2 of cvreala (Aim-rivun). 



Canna seed, etc. M. Mansfeld 3 reported the presence of canna seed in 

 a coft'ee, and in an examination made in Austria, sawdust, oak bark, 

 baked liver, etc. Hassall 4 mentions the use of 'sawdust, etc., in the adnl 



1 Food, Arthur H. Hassall, Longmans, Green & Co., London, p. 167. 

 ' J Dictionary of Applied Chemistry, Thorpe, 1, 490. Analyses by Cliflurd llich- 

 imhon, TJ. 8. Department, of Agriculture. 

 :1 l.Yv. Int. Scien. el I'nji. des Falsification, 4, 10. 

 4 Habball, Food, p. 159. 



