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VI. 



PRODUCTION OF AMMONIA FROM ATMOSPHERIC NITROGEN . 



By HERMAN C. WOLTERECK, Ph.D. 



[communicated by professor HUGH RYAN, M.A., D.SC] 



Read December 22, 1908. Ordered for Publication Feekuary 15. Published April 3, 1909. 



This process was developed by the investigation of certain observations made 

 in the course of experiments for the synthetical production of hydrocyanic 

 acid, which were carried out by Professor Esohweiler and myself in 1900 at 

 the Technische Hochschule, Hanover. In the course of our observations it 

 was found that ammonia is always formed when a dry mixture of hydrogen 

 and nitrogen is passed over so-called reduced iron suspended on asbestos fibre, 

 and heated to a temperature approaching dark-red heat (about 500° C). This 

 forms an excellent lecture experiment, as it requires little preparation and 

 time, and gives a very strong reaction with nesslerized water a few minutes 

 after starting the experiment. Sir William Ramsay, in October, 1901, was 

 kind enough to verify this observation, and produced 11 mg. of ammonia in 

 his laboratory by this method. However, this reaction is fugitive, and the 

 formation of ammonia stops after a certain time. 



On modifying these experiments, and starting with iron oxide, over which 

 a mixture of air and coal-gas was passed, larger quantities of ammonia were 

 obtained. This led to a series of experiments with different metallic oxides. 

 It was found that under the above conditions ammonia was produced by the 

 oxides of the following metals : — nickel, cobalt, copper, cadmium, silver, lead, 

 bismuth, chromium, and iron — the last three giving the best results. 



The experiments were generally arranged in such a manner that the 

 oxide was supported by asbestos fibre in a combustion-tube which was heated 

 to dull red heat. Illuminating gas and air in about equal quantities, after 

 having been passed tlirough dilute sulphuric acid previously tested for 

 nitrogen compounds, were passed over the oxide, which in most cases^became 

 incandescent. Water was condensed and collected in a IJ tube arranged 

 behind the combustion tube, and gave a distinct alkaline reaction after several 

 hours' duration of the experiment. The use of glass combustion-tubes proved 

 very inconvenient on account of their frequent breakage by the condensed 



