248 Apparatus for Preparation of Pure Nitrogen. 



Freshly-boiled distilled water is introduced into the apparatus,, 

 specially cleaned and dried through the reservoir with the^ 

 tap T 4 closed. The apparatus is filled up to T 2 , which is then 

 closed just before water contaminates it by contact (T 2 and T a 

 being greased vacuum taps). By suction from the top of the- 



Fi-. 1. 



separating funnel with T 1 open, water-is made to displace the 

 air in the loop and stem upwards, and T 1 is closed. The excess 

 water in reservoir is then drawn off through tap T 4 up to the 

 level K, and strong ammonia introduced into the reservoir,, 

 which, mixing with the distilled water, makes Gr completely 

 filled with dilute ammonia. The separating funnel is charged 

 with bromine water, 



On opening T x and allowing a few drops of the bromine 

 water to run into G, by interaction with ammonia, nitrogen 

 is evolved slowly which collects on the top of Gr up to the 

 tap T 2 . By opening T 3 to the vacuum, P gets exhausted ; and 



