12 



TRANSACTIONS OF WAGNER 



FOOD FROM THE AIR 



The details of the most recent practical application of this method have 

 been withheld almost entirely owing to the fact that it has been operated in 

 Germany, and the data concealed on account of the war. It is known that a 

 large plant was erected near Ludwigshafen by the Badische Anilin und Soda 

 Fabrik, and it is stated by Gilbert (see bibliography) that the latest report 

 gave 200,000 tons of ammonium sulfate as a year's output. This corresponds 

 to about 50,000 tons of synthetic ammonia. 



The choice of catalyst is Hmited. Haber and Le Rossignol found 

 osmium the most active of those they tried, but its high cost is a serious ob- 



Pump for circulating gas 

 200 atmospheras 



llQUUt 

 NH, 



Ammonia outlet 



Haber & Le Rossignol process for synthetic ammonia. 

 Martin & Barbour. Industrial Nitrogen Compounds, 54. 



jection. It has fortunately been found that commercial metaUic uranium will 

 act very well. The enormous pressure required introduced practical diffi- 

 culties which have been overcome by very careful construction of the pressure 

 containers and, it is stated, avoiding the dangers of explosion by bur3dng these 

 in the ground. 



As large amounts of heat and mechanical energy are not required for this 

 process, it is capable of exploitation in many parts of the world, not being con- 

 fined to districts in which cheap water-power is available. 



The annexed diagrammatic illustration will show the general method. 

 For reasons noted above, information as to exact construction and operation 



