CH. IV] 



LOSS COMPARED WITH ABSORPTION. 



99 



may be present. Let it remain in water for 24 hours, cut 

 a fresh surface and fit it in a bottle arranged as in fig. 18. 

 The branch B fits a tube which pierces the cork and 



FIG. 18. Exp. 115. 



should dip well into the water in the bottle 1 . Through 

 another hole in the cork a tube T graduated into -fa c.c. 

 and holding about 20 c.c. is passed : this serves to record 

 the amount of water absorbed by B : the opening of T 

 must be closed with a plug of cotton- wool to allow air to 

 enter, and yet to check evaporation from T, In one experi- 

 ment we found that a branch of laurel with 30 leaves 



1 In fig. 18 the tubes do not dip sufficiently deep. 



72 



