9. (a) Lay a piece of paper on the radiator or some other warm surface. Rub the meat 

 of an English walnut over the warmed paper. Infer concerning the presence of fat. (b) Re- 

 peat, using the "germs" of kernels of corn. Infer concerning the presence of fat in the 

 "germ." (c) In a similar manner test oatmeal. Infer concerning the presence of fat in oats. 



Part E. Carbon an Element Present in All Foods Stored by Plants. 



10. (Classroom experiment.) Burn a small quantity of starch in a spoon, (a) Observe 

 what is left in the spoon, (b) Compare the substance remaining, with a sample of charcoal. 

 Charcoal is almost pure carbon, (c) From what source did the plant obtain the carbon? (d) 

 Hold some charcoal (carbon) in a hot flame for some time. Does it burn? 



11. Treat a small quantity of sugar as in 10 above. Compare the result of burning sugar 

 with that of burning starch. 



12. Saturate a piece of filter paper with olive oil. Light the paper, (a) Observe the 

 color of the smoke given off by the oil. Hold an evaporating dish in the smoke, (b) Ob- 

 serve the nature of the substance deposited upon it. 



13. Exp. 10, 11, and 12 above show the presence of what element in the plant foods 

 studied? 



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