STUDY OF NUTRIENTS 29 



takes place, note the final color. Test in the same way oil, 

 starch, and any other substance that contains no grape 

 sugar. Compare results. 



(This is a universal test for grape sugar.) 



XVI. — ^Fats and Oils. 



Apparatus. — Flaxseed (ground), beef fat, unglazed paper, ben- 

 zine, filter paper, glass funnel, evaporating dish, chemical ther- 

 mometer. 



Directions. — A. Put a Uttle beef fat in the evaporating 

 dish and heat. When it begins to melt stir with the chemi- 

 cal thermometer and note the temperature of the melting 

 point. If the body temperature is 98° F. what does this 

 experiment indicate as to the condition of fats in the body? 

 Name some fats that are liquid at ordinary temperatures. 



B. Place a little beef fat on the unglazed paper and 

 warm. Remove and examine the paper. How does it 

 show the presence of fat? Substitute for the beef fat a 

 little ground flaxseed and repeat the above process. Does 

 flaxseed act like beef fat? Do starch and other substances 

 which contain no fat or oil, act in the same way? (The 

 above is a general test for fats and oils in whatever form 

 they may be.) 



C. Place a teaspoonful of ground flaxseed in the evapo- 

 rating dish and cover with benzine. (Ether will act in 

 the same way.) Cover the dish and allow it to stand for a 

 few hours. At the end of that time, filter off the benzine 

 by means of the funnel and filter paper, into a clean evapo- 

 rating dish. Allow this dish of filtered benzine to stand 

 for a time until all the benzine has evaporated. What is 



