252 POODS AND DIETARIES 



4. Used to make peas and beans greener (copper). 



5. Used to color poor butter. 



6. Added to chopped meats, sausage, etc., to give fresh color. 



d. Some Simple Tests 



1. Put some chloroform in tomato catsup or other table sauces 

 and shake it vigorously, pour it off into a saucer and let it stand 

 until it evaporates. If crystals are left, they are probably 

 benzoic acid. 



2. Put a teaspoonful of milk in a teacup, with twice the 

 amount of HC1 to which has been added a drop of ferric chlo- 

 ride. Mix them by rotating the cup gently. Put the cup 

 in a vessel of boiling water and let it stand for 5 minutes. 

 If formaldehyde is present, it will be shown by purple or 

 lavender color. 



3. Mash some canned peas or string beans with a spoon. 

 Put a teaspoonful of it in a teacup with 3 teaspoonfuls of water 

 and 30 drops of HC1. Set the cup in a pan of boiling water. 

 Drop a bright iron nail into the cup and keep the water boiling 

 for a few minutes, stirring the mixture frequently ; if copper 

 is present, it will plate the nail copper color. 



4. (a) Stew \ teaspoonful of ground coffee in one half cup of 

 boiling water and cool. Dilute with water, if it is dark colored, 

 and add iodine solution drop by drop. Color ? Conclusion ? 



(6) Same for ground cloves, mustard, cayenne, etc. 



(c) Add a teaspoonful of finely ground coffee to one half 

 glass of cold water. Pure coffee will float, and its adulterants, 

 chickory, roasted cereals, etc., will sink. Pure coffee will not 

 appreciably color the water, while chicory will leave a brownish 

 trail as it sinks. Limit test to 5 minutes. 



5. Place a tablespoonful of tea in a wide-mouthed bottle and 

 shake it with six times its volume of cold water. Strain the 

 water through a sieve and any insoluble mineral substances 

 used on the leaves will settle. 



6 Put some butter or oleomargarine in a spoon and heat 

 over a lamp. If it is fresh butter it will boil quietly with much 



