88 MODERN SCIENCE READER 



of twenty-one per cent., while the liquid nitrogen collected 

 at C" is poured out from the top of the column, and submits 

 the gases at twenty-one per cent, to a further rectification. 



After having been washed by pure liquid nitrogen, the 

 gas finally becomes itself pure nitrogen gas, coming out of 

 the apparatus at E. 



The pure oxygen resulting from rectification at the bot- 

 tom of the column is vaporized at "F, the greater part of it 

 entering the column of rectification, while the remainder 

 comes out at T and is then collected. 



By this means an integral separation of atmospheric air 

 into its constituents, pure oxygen and pure nitrogen, is 

 carried out. 



Figure 5 illustrates a plant which is able to turn out 

 each hour as much as 50 cubic meters (1,776 cubic feet) 

 of oxygen. 



