464 



Introduction to the Study of Science 



What do the results show? How much water is lost in a day? 

 Does it seem to depend upon the temperature of the room where the 



plant is kept? Does it vary 

 by day and by night? 



The same fact may be shown 

 with the apparatus illustrated 

 in Fig. 148. Select a stem or 

 shoot that is fresh and plenti- 

 fully supplied with leaves. See 

 that the corks fit close to pre- 

 vent escape of water except 

 through the branch. Mark the 

 place the water reaches in the 

 tubing. Set the apparatus in a 

 good clear light. 



Table of materials used by 

 plants. The quantities of 

 materials that plants remove 

 from the soil, the amount of 

 soil water utilized and re- 

 leased through transpiration 

 and evaporation, and its 



FIG. 148. Arrangement of apparatus to equivalent in inches of rain- 

 show transpiration. 



following table, 

 per acre. 



fall, are presented in the 

 The crops are expressed in bushels or pounds 



