NITRIC OXIDE AND SODIUM AMALGAM. 323 



The method of experiment was as follows : — A stream of nitric 

 oxide was passed through a bent tube, containing the sodium 

 amalgam and alcohol, jjreviously freed from all traces of air by a 

 current of hydrogen passed through purifying and deoxidising 

 agents. The product of the reaction, sodium hyponitrite, as it 

 formed, separated out in the alcohol as a white finely- divided pre- 

 cipitate. 



Although water was used in the first instance, this method of 

 experiment was abandoned owing to the small yield of sodium 

 hyponitrite (-54 per cent, of the theoretical yield) and the gradual 

 decomposition of the soluble salt so formed in the presence of 

 nascent hydrogen. By using absolute alcohol in place of water 

 the yield was increased to 6 per cent, of the theoretical, and the 

 decomposition above mentioned avoided A small volume of nitric 

 oxide (82-5c.c.) left in contact for forty-two hours with sodium 

 amalgam and alcohol entirely disappeared, as such, with the pro- 

 duction of about half its volume of nitrogen. All amalgams used 

 contained less than 1 per cent, of sodium, and the duration of each 

 experiment was some two hours ; with stronger amalgams (3 per 

 cent, to 4 per cent.), no yield of hyponitrite was obtained. 



An experiment in which some 8 litres of nitx-ic oxide were 

 left in contact for nine days, under slightly increased pressure, with 

 1,470 grammes of amalgam and 150c. c. of alcohol, gave somewhat 

 unlooked-for results. The sodium compound produced, which was 

 found to contain no trace of mercury, while resembling sodium 

 hyponitrite in respect to its being a white comjDJund insoluble in 

 alcohol and readily soluble in water, possessed other properties 

 of a very peculiar nature in no respect resembling hyponitrite. 

 While kept under alcohol it was somewhat flocculent in appearance, 

 but immediately on exposure to air became of a pitch-like consis- 

 tency, insoluble in ether and benzine even on boiling. When 

 heated it swells up, and at a moderate temperature decomposes 

 explosively. It is decomposed by both strong and dilute mineral 

 acids, the former action being very energetic. 



Reactions with solutions of mineral salts : — Silver nitrate — A 

 white precipitate, soluble in excess of the sodium salt ; readily 

 soluble in either dilute nitric acid or ammonia, and reprecipitated 

 on neutralisation as a chocolate-colored precipitate. The white 

 preciiDitate when dry blackens immediately on exposure to light, 

 and is explosive at a moderate heat. Copper sulphate produces a 

 green preciintate, and ferric chloride a brown precipitate closely 

 resembling the hydrate in appearance. Lead acetate gives a dirty- 

 white precipitate, while with mercuric chloride no reaction takes 

 place. 



The absorption of nitric oxide, judging from a curve constructed, 

 was very regular, and the gaseous products of the change were 

 found to be ammonia and nitrogen, the latter by rough measure- 

 ments being about half the volume of nitric oxide absorbed. 



