Vol. VI, No. 11.] Reactions in presence of Nickel. 595 



[N.S.] 



The air was expelled from the entire apparatus by means 

 of hydrogen while the tube was not heated. The hydrogen 

 was stopped and the mixture of hydrogen and nitrogen was 

 then slowly admitted to replace hydrogen. The tube was then 

 heated to dull red heat. After some time the Nessler's solution 

 was found to be clouded with a whitish precipitate and a strong 

 tarry smell was perceived. We are not sure if this whitish precipi- 

 tate led Ramsay and Young who used iron filings to think that 

 ammonia was being formed. The tarry smell suggested to us the 

 possibility of the formation of hydro-carbons by the combination 

 of hydrogen with traces of carbon contained in the iron. In 

 order to establish this, fresh experiments were started in which 

 the tube containing the iron was strongly heated in the current 

 of hydrogen as long as the tarry smell was perceived and the 

 whitish precipitate was formed in the Nessler's solution. When 

 the smell was no longer perceived, the mixture of nitrogen and 

 hydrogen was passed for about four hours. The Nessler's solu- 

 tion remained unchanged, there was no smell of ammonia, and 

 red litmus paper was unaffected. The following variations of 

 the experiment were tried with the following results : 



(i) Pure iron wire was used in the place of reduced iron, 



the same tarry smell and precipitate when heated in 



a current of hydrogen. No ammonia, 

 (ii) Pure ferric oxide was reduced by hydrogen. No 



tarry smell. No ammonia. 



(iii) The gases were dried by omitting the wash-bottle 



containing water. Still no ammonia. 



(iv) The temperature was varied from dull red heat to 



bright red heat using a combustion furnace, no 

 ammonia. Ramsay and Young heated the tube red 

 hot, though ammonia begins to decompose at 



500 



presence of 



The experiments were repeated, using nickel obtained by 

 the reduction of nickel oxide in hydrogen, nickel wire and 

 nickel obtained by electrolysis. There was no sign of the 

 formation of ammonia. 



Reduction of Nitric Oxide in presence of Nickel. 



Sabatier and Sanderens showed that marsh gas is formed 

 by the reduction of carbon monoxide and dioxide in presence 

 of nickel reduced by means of hydrogen. We have here 

 studied if the oxides of nitrogen, sulphur and phosphorous 

 are also reduced in presence of reduced nickel. 



Nitric oxide has been reduced to ammonia by means of 

 hydrogen in presence of such porous substances as spongy 



