1871.] 



Dr. Divers on Salts of Nitrous Oocide. 



429 



The solution acidified with acetic or hydrochloric acid still gives no re- 

 action with potassium iodide, decolorizes iodine solutions, and prevents 

 the action of a nitrite on an iodide. 



The acidified solution gives no coloration with ferrous sulphate. In con- 

 tact with strong sulphuric acid, the mixture gives the coloration like a 

 nitrate. As is well known, a nitrite, even without addition of acid, gives 

 an immediate colour with ferrous sulphate. 



The acidified solution immediately decolorizes potassium permanganate. 



The acidified solution does not reduce potassium dichromate. 



The solution which has been neutralized with nitric acid instead of acetic 

 acid will not do for the iron and iodine tests, as this behaves, so far as it 

 has been tried, as though it contained a nitrite. 



The acidified acetic-acid solution, when heated, evolves nitrous oxide. 

 Here again, therefore, the new salt is analogous to a carbonate, — 

 2NOH=N 2 + OH 2 . 



8. When silver nitrite is heated until a greenish -yellow, semifused mass 

 remains, and this is washed out with water, the residue consists of metallic 

 silver and a little bright yellow matter, unaffected by light, soluble in am- 

 monia, and decomposed by boiling in water, as will be found described in 

 my paper on the action of heat on silver nitrite already referred to. From 

 the properties of this yellow substance, and from the manner in which it 

 is formed, it is probable that it is the silver-salt of the new acid ; but in 

 consequence of the small quantity of it obtainable, and of the admixture of 

 this with metallic silver, a fuller examination of it has not been attempted. 

 If it be this salt, its formation is analogous to that of silver nitrite by 

 heating silver nitrate. 



9. There is also reason for believing that Hess * came across this salt 

 by first treating a solution of barium nitrate which had been deoxidized by 

 heat with a solution of silver sulphate and evaporating the mixture, and 

 then decomposing the crystals thus obtained by the action of water. 



10. In his ' Researches on Nitrous Oxide 'f, Sir Humphry Davy de- 

 scribed some experiments by which he obtained what appeared to him to 

 be a combination of nitrous oxide with potash. He prepared it by ex- 

 posing a mixture of solid potassium hydrate and potassium sulphite to the 

 prolonged action of nitric oxide, dissolving the resulting product in water, 

 crystallizing out the potassium sulphate formed, and then evaporating to 

 dryness. The mass thus obtained evolved when heated pure nitrous oxide, 

 amounting to about a fourth of its weight. 



Since then, however, Pelouze % has obtained, by a modification of Davy's 

 method, the alkali nitrosulphates ; and it seems to be now universally 

 * Fogg. Ann. vol. xii. (1828) p. 257. 



f Kesearches, Chemical and Philosophical, chiefly concerning Nitrous Oxide (1800). 

 Res. ii. Div. i. sect. 6, pp. 254-277. 



J " Sur quelques combinaisons d'un nouvel Acide forme d' Azote, de Soufre et d'Oxy- 

 gene," Ann. de Chim. et de Phys. vol. lx. (1835) p. 151. 



