FOOD ANALYSIS 265 



order that we may consume a sufficient quantity of the right 

 kinds. 



There is always a temptation to adulterate food offered for 

 sale, as well as to color it artificially, and also to add preserva- 

 tives which may affect the health of the consumer. Nearly 

 all of the foreign matter can be detected by the proper test, 

 and the tests for the common substances are given in Experi- 

 ment 87. 



References : 



1. 1501:111-112. Adulteration of Milk. 



2. 1503 : 21-22. Tests for Nutrients. 



3. 1503 : 323-324. Adulterations in Food. 



4. 1605 : 282-287. Compositions of Food the" Use of Each 



Part. 



5. 1710:123-125. Kinds of Foods. 



6. 1710 : 242-250. Milk Analysis and Tests. 



7. 1710 : 304-307. Tests for Preservatives and Coloring Matter 



in Foods. 



8. Farmers' Bulletin No. 131. Tests on Butter. 



9. Office of Experiment Stations, Bulletin No. 162. Studies on 



Meat. 



a. 1505 : 93-94. Adulteration of Food. 



b. 1506 : 42-43. Adulteration of Food. 



c. 1507 : 46-48. Composition of Common Foods. 



d. 1509 : 83-86. Tests on Food. 



Experiment 86. Composition of Food. 



Apparatus : Ring stand, burner, asbestos mat, evaporating 

 dish, test tubes, beaker, 100 c.c., flask 150 c.c., funnel, filter 

 paper. 



Materials : Iodine solution (make a 10 per cent solution of 

 potassium iodide, dissolve as much iodine in it as possible, and 

 then dilute with nine times as much water). Fehling's so- 

 lution (make three stock solutions: (1) copper sulphate, 



