THE WORK OP LEAVES 95 



and since little or none escapes from the stems of plants, 

 we may say that that which is lost from the pot is given 

 off by the leaves. 



Carefully weigh the flower pot and plant. Remove 

 the cork from the glass tube each day, pour water through 



Fig. 3U. — The water lost by leaves. 



it into the soil, keeping an accurate record of the weight 

 of the water so added, and being careful to replace the 

 cork each time. At the end of a week, weigh the plant 

 and pot again, and from the figures which you will now 

 have, determine the amount of water given off by the 

 leaves during that time. Measure as accurately as 

 possible the number of square inches of leaf surface on the 

 plant. 



