SUMMARY 



13 



At the beginning of the experiment the nitrogen must 

 be removed from the water and the plant by means of an 

 air-pump. After this the gas evolved is found to be pure 

 oxygen. 



The cut end of the plant is placed in the plant-vessel so 

 that it is only 2 mm. below the surface of the water. The 

 short length of water soon becomes saturated with oxygen, 

 after which there is no loss by absorption. 



