342 Lord Rayleigh. On an Anomaly < //< -omit* ,>/ /// [Apr. 



into atmospheric nitrogen, seem to prove conclusively that the 

 burning would really take place. Some further experiments of tl 

 same kind will presently be given. 



The gas from ammonia and oxygen was sometimes odourless, 

 at other times smelt strongly of nitrons fumes, and, after mixtut 

 with moist air, reddened litmus paper. On one occasion the oxidatic 

 of the nitrogen went so far that the gas showed colour in the blow- 

 tube of the Toppler, although the thickness of the layer was onlj 

 about half an inch. But the presence of nitric oxide is, of coin 

 no explanation of the abnormal lightness. The conditions unc 

 which the oxidation takes place proved to be difficult of control, at 

 it was thought desirable to examine nitrogen derived by reductic 

 from nitric and nitrous oxides. 



The former source was the first experimented upon. The gas 

 evolved from copper and diluted nitric acid in the usual way, 

 after passing through potash, was i-ednced by iron, copper not beii 

 sufficiently active, at least without a very high temperature, 

 iron- was prepared from blacksmith's scale. In order to get quit 

 carbon, it was first treated with a current of oxygen at a red ht 

 and afterwards reduced by hydrogen, the reduction being repeat 

 after each employment. The greater part of the work of reducing i 

 gas was performed outside the furnace, in a tube heated locally with 

 Bunsen flame. In the passage through the furnace in a tube 

 taining similar iron the work would be completed, if necessi 

 Next followed washing with sulphuric acid (as required in the ammonia 

 process), a second passage through the furnace over copper oxide, 

 further washing with sulphuric acid. In order to obtain an indie 

 tion of any unreduced nitric oxide, a wash-bottle containing ferret 

 sulphate was introduced, after which followed the Nessler test 

 drying tubes, as already described. As thus arranged, the apparat 

 could be employed without alteration, whether the nitrogen to 

 collected was derived from air, from ammonia, from nitric oxid 

 from nitrous oxide, or from ammonium nitrite. 



The numbers which follow are the weights of the gas contained 

 the globe at zero, at the pressure defined by the manometer when 

 temperature is 15. They are corrected for the errors in the weight 

 but not for the shrinkage of the globe when exhausted, and tht 

 correspond to the number 2 - 3l026, as formerly given for nitrogen. 



Nitrogen from NO by Hot Iron. 



November 29, 1893 2'30143-| 



December 2, 1893 2'29890 I 



December 5, 1893 2'29816 f Mean ' 2 30 



December 6, 1893 2'3018'J J 



