60 



PLANT GROWTH AND NUTRITION 



perature, all organic material disappears ; the remainder is ash or 

 mineral matter. 



Problem 31 : To test for the presence of water. 



Materials. — Meat, oven, balance. 



Method. — Weigh a piece of meat. Place it in a warm oven 

 until it is thoroughly dry, then re weigh it. 



Observations. — What percentage of its original weight does 

 the meat lose ? 



Conclusion. — 1 . What is the cause of most of the loss in weight ? 



2. As a result of your experiments, write a short statement as 

 to what organic and inorganic nutrients are present in the bean. 



3. What happens to the nutrients when the young plant grows? 

 Give reasons for your answers. 



Problem 32: To 

 test various food sub- 

 stances for the or- 

 ganic nutrients. 

 (Home Work.) 



Materials. — Pupils 

 may be supplied with 

 testing chemicals to 

 take home or this exer- 

 cise may well be a lab- 

 oratory exercise. 



Method and Obser- 

 vations. — Test with 

 chemicals, as above, 

 as many different foods 

 as possible, said foods 

 to include meats, ce- 

 reals, nuts, vegetables, 

 fruits. Make a table 

 like the accompanying. 

 After testing a food for 

 a given nutrient place 

 one of the three fol- 



