98 COMPOUND ORGANS OF PLANTS. 



Fig. 14. 









Fig. 14. Experiment of Hales to show the force with which the ?ap ascends, c. Stock 

 of vine cut. t. Tube with double curvature fastened to the top of the stock by a 

 copper cap v, which is secured by a lute and piece of bladder m. n n. Leve' of the 

 mercurial column in the two branches of the tube at the commencement of the experi- 

 ment, n' n' Level at its close . 



