COMPOSITION OF LIFELESS AND LIVING THINGS 19 



4. (Optional.) Prepare in your note-book a table like the follow- 

 ing, and place in the proper columns the names of the 

 foods tested in class. 



26. To test foods for fats. Laboratory Study No. 11. 

 Suggested as home work. 



Materials : Butter or olive oil, corn starch, grape sugar, piece of 

 boiled white of egg, salt, water ; various foods in the home kitchen, 

 including nuts. 



1. Put on a piece of paper a piece of butter half the size of 



a pea (or a drop of olive oil). Put the paper in a 

 warm place (e.g. in a hot oven or over a heated radi- 

 ator) for a few moments, then hold the paper between 

 yourself and the light. How is the paper affected by 

 the fat? 



2. Try the effect of each of the other food substances (starch, 



grape sugar, piece of boiled egg, i.e. protein, salt, i.e. 

 mineral matter, water) on paper, by adding an equal 

 quantity (half the size of a pea) of each to separate 

 pieces of paper. Put the pieces of paper in a warm 

 place as in 1 above. Hold each piece between yourself 

 and the light. Do any of these food substances affect 

 the paper as did the fat ? 



3. From the preceding experiments state how you can de- 



termine whether or not a food contains fat. 



4. (Optional.) Prepare in your note-book a table like the follow- 



ing, and place in the proper columns the names of the foods 

 tested at home or in class. 



