426 



Dr. Divers on Salts of Nitrous Oxide. [Apr. 20, 



4. After neutralizing the alkaline liquid by acetic acid, it gives a yellow, 

 pulverulent precipitate with silver nitrate. This precipitate, when thoroughly 

 washed from its saline mother liquor, is almost as insoluble in water as silver 

 chloride ; for hydrochloric acid gives no immediate opalescence with water 

 filtered through it. It is quite stable below 100° C, or a little lower than 

 this, and it may be washed with hot water without change. It is also un- 

 affected by light, or by exposure to a pure atmosphere, even when in contact 

 with paper. It is but very sparingly soluble in acetic acid ; so that this acid 

 may be added in excess to the original alkaline liquid without removing its 

 property of being precipitated by silver salts. It is soluble in ammonia 

 and ammonium carbonate, from solution in either of which it can be again 

 thrown down by acetic acid, or by cautious neutralization of the ammonia 

 by dilute nitric or sulphuric acid, or by the volatilization of the ammonia. 

 It is soluble in either dilute nitric or sulphuric acid, and without immediate 

 decomposition ; and it can be reprecipitated from its solution in either of 

 these acids by the cautious addition of ammonia or ammonium carbonate, or 

 by the free addition of sodium carbonate or sodium hydrate, in either of 

 which it is insoluble. It is immediately oxidized by concentrated nitric 

 acid, copious red fumes being produced. Moderately diluted nitric, sul- 

 phuric, or hydrochloric acid decomposes it, with the evolution of nitrogen, 

 and the production of apparently both nitrous and nitric acids in the solu- 

 tion. It is also decomposed by soluble chlorides and by hydrosulphuric 

 acid. When precipitated from the original liquid, it sometimes becomes 

 dark-coloured ; but this change is due to the formation of a black matter 

 derived from the sodium or naphtha and the silver acetate. After washing 

 it, dissolving it in very dilute nitric acid, and filtering the solution, it may 

 be reobtained by the cautious addition of ammonia, or by the addition of 

 ammonia to alkaline reaction and then a little acetic acid, in a condition in 

 which it is no longer liable to discoloration. It is decomposed by a mode- 

 rate heat into nitric oxide, metallic silver, and a little silver nitrate — in this 

 respect resembling silver nitrite. My experiments on silver nitrite, about 

 being published, show that nitric oxide may serve as a carrier of atmospheric 

 oxygen to silver nitrite ; and it is therefore most probable that in this case 

 also some of the nitric oxide liberated serves to carry a little oxygen to the 

 still undecomposed new silver-salt. During its decomposition by heat it 

 does not fuse or exhibit any other change except that from a bright yellow 

 to a silver-white colour. After a red heat nothing remains but pure silver. 



5. The following determinations of the amount of silver in the salt have 

 been made : — 



I. *33 1 7 grm., dried at a gentle heat, was suspended in water and digested 



ride, phosphate, and sulphate, that any ammonium salt would give ammonium amal- 

 gam with sodium amalgam. Ammonium nitrate yields no ammonium amalgam with 

 sodium amalgam ; more than this, the presence of a nitrate prevents the formation of 

 this body by other salts of ammonium. 



