36 FIRST YEAR COURSE IN GENERAL SCIENCE 



hours, by opening a window near it or laying upon it for a 

 few minutes a cloth wrung out in cold water. 



1. Weight of the dish g. 



(a) " " " " and leaves g. 



(6) " " " " " " g. 



(c) " " " " " " g. 



(d) " " " " " " g. 



RESULTS 



1. What change in the weight of the leaves occurred? 

 What do you think was the cause of the change? 



2. Would there be as great a change in the weight of 

 leaves left on a plant? Why? 



3. What per cent of the original weight was lost the 

 first day? Was it the same per cent every day? 



4. Supposing no further change to occur after you finished 

 weighing, from your figures calculate the per cent of weight 

 of water in green leaves. 



5. In Case 2, why should the pot be enclosed in rubber? 



6. What was the evidence of escape of water from the 

 plant leaves? 



7. In what form did the water escape? Tell how you 

 know. 



8. Where does the water enter the plant? 



9. What becomes of the mineral matter dissolved in 

 water which plants take up? 



10.. What function of leaves has this experiment illustrated? 



EXERCISE XXVIII (Textbook 307) 

 TEST FOR FOOD MATERIAL IN SEEDS 



MATERIALS: Concentrated nitric acid; ammonia solu- 

 tion; solution of iodine; some means of warming and press- 

 ing (flatiron) ; various seed foods such as oatmeal, peanuts, 

 beans, nuts. 



