TEANSACTIONS OF SECTION B. 717 



the hydrate. On rubbing it is more gritty than iron prepared as above. It is 

 feebly magnetic. 



Heated in hydrogen, ammonia is produced at about the same temperature as 

 that at which the nitride is formed. 



It readily bums in chlorine, ferric chloride and nitrogen being formed. 



Heated in carbon monoxide, no evidence of the formation of cyanogen com- 

 pounds could be obtained. 



Steam at 100° slowly oxidises the nitride with evolution of ammonia. 



Hydrogen sulphide begins to react with it at 200°, forming ammonium sulphide 

 and sulphide of iron. 



Heated in nitrogen to the boiling-point of sulphur, no change occurs. The 

 temperature at which nitrogen is evolved by the action of heat alone must there- 

 fore be above this point. 



An ethereal solution of iodine is without action upon the nitride. 



From a slightly acidified solution of copper sulphate, nitride of iron deposits 

 copper. 



Heated with ethyl iodide to 200° in a sealed tube, defines are formed, and 

 iodides of iron and ammonium, the reaction evidently being 



5C2H,I + Fe^N = 2FeI„ + NHJ + SC.H^ + H. 



Heated similarly to 200° with phenol no reaction occurred. 



Treated with a mixture of hydrogen peroxide and sulphuric acid, analyses 

 showed that very little, if any, of the nitrogen is oxidised, the whole dissolving as 

 usual to form ammonium sulphate. 



In conjunction with Mr. P. J. Hartog, the author has determined the heat of 

 formation of the nitride by dissolving it in sulphuric acid contained in a platinum 

 calorimeter, and observing the rise of temperature. Three well-agreeing experi- 

 ments showed that the substance is formed with evolution of about three calories. 



In general the nitride of iron behaves as an ammonia derivative, the nitrogen 

 being either evolved in the free state, or converted into ammonium compounds, 

 according to circumstances. 



Its constitution may possibly be 



Fev^ yFe 



Fe/ \Fe 



> 



5. Eeport on the Silent Discharge of Electricity in Oxygen and other Gases, 



See Reports, p. 439. 



FRIDAY, SEPTEMBER 15. 



The following Reports and Papers were read : — 

 1. Beport on the Action of Light upon Dyed Colours. — See Reports, p. 373» 



2. Demonstration of the Preparation and Properties of Fluorine hy Moissan's 

 Method. By Dr. M. Meslans. 



3. Interim Report on the Formation of Hold Is, 

 Th? Committee desired reappointment, a9 their work is unfinished. 



