{the Hydrate of) Stdphiric Acidixith Nitric Oxide. 85 



If this crystalline saline mass was treated in a dry glass 

 gradually with water, nitric oxide was evolved, and there was 

 formed, according to the quantity of water, a green, blue, 

 and lastly, a colourless liquid. The crystalline mass dissolves 

 in concentrated sulphuric acid without decomposition; and, 

 if the solution be subjected to distillation, the superfluous sul- 

 phuric acid, contaminated by some sulphate of nitric oxide, first 

 passes over, and then the concentrated solution of the sulphate 

 of nitric oxide in sulphuric acid, which can be distilled over 

 several times without decomposition. This solution, as well as 

 the crystalline mass, was tested for nitric and nitrous acids 

 in the manner previously described, without, however, a trace 

 of them being discovered. As a counter-experiment here like- 

 wise, as always subsequently, a drop of nitric acid was added 

 to the one half of the diluted solution, and both portions were 

 boiled for an equal length of time. In the portion to which 

 nitric acid had been added, I naturally obtained with sul- 

 phuric acid, and a solution of copperas, a deep brownish-black 

 colouring ; in the other portion not the slightest trace of it. 



The sulphate of nitric oxide is, it is true, decomposed as 

 rapidly b}' water as its solution in sulphuric acid ; yet the de- 

 composition does not seem to be effected perfectly in the cold ; 

 if, however, a great quantity of water be employed for dilu- 

 tion, and it be boiled somewhat longer, every trace of nitric 

 oxide at last escapes. But so long as one of the oxides of 

 nitrogen is detected in the solution, by means of sulphuric acid 

 and copperas, the solution of the permanganate of potash is 

 decolorated by it. 



The combination of nitric oxide with anhydrous sulphuric 

 acid, prepared by Prof. H. Rose, acts, according to the ex- 

 periments I have made with it, in exactly the same manner. 

 On dilution with water the same play of colours occurs under 

 disengagement of nitric oxide; and if the diluted solution be 

 boiled for some minutes, all the nitric oxide escapes, and the 

 solution of copperas with sulphuric acid does not indicate any 

 nitric acid in the boiled liquid. Likewise, in this case, the 

 sulphate of the nitric oxide is more completely decomposed, 

 English sulphuric acid being present. If the crystalline mass 

 was diluted with much water, and heated only ibr a moment 

 without sulphuric acid, it was, it is true, coloured by copperas 

 and sulpliuric acid, but then the cooled liquid also still disco- 

 loured a dilute solution of the permanganate of jiotash ; as 

 soon as this, after longer boiling of the cooletl liquid, was no 

 longer discoloured, did copperas and sulphuric acid likewise 

 cease to react. 



Since these crystals acted exactly in the same manner as 



