FORMED OF AZOTE, SULPHUR, AND OXYGEN. 473 



duce one atom of a peculiar acid, composed of two atoms of azote, one 

 atom of sulphur, and four atoms of oxygen. This assumption has been 

 verified by the direct analysis of the salts. I call this acid nitrosul- 

 phuric, and the salts which it forms nitrosulphates. 



Nitrosulphate of Ammonia. 



The nitrosulphate of ammonia is a white salt, of a sharp and 

 slightly bitter taste, with nothing of that of the sulphites ; it does not 

 act upon either litmus or turmeric paper ; it crystallizes in prisms, 

 with bases of oblique-angular parallelograms, more or less flattened, 

 and terminated in different manners. It is insoluble in alcohol, either 

 warm or cold ; it is easily dissolved in water, in which it finally de- 

 composes, with a rapidity proportioned to the elevation of the tem- 

 perature : the water retains sulphate of ammonia, whilst it disengages 

 a gas which has the properties of the protoxide of azote. Alcohol pre- 

 cipitates this salt from its aqueous solution. Exposed to a tempera- 

 ture of 110°, it resists, but at a few degrees above that point it decom- 

 poses with an explosion, caused by the rapid disengagement of prot- 

 oxide of azote. If thrown upon red-hot coals, it burns with scintilla- 

 tion. 



All the acids disengage from it protoxide of azote, and cause it to 

 pass into the state of sulphate of ammonia ; this decomposition is slow 

 with carbonic acid gas, but it proceeds with rapidity when it is dis- 

 solved in water. In the open air the nitrosulphate of ammonia decom- 

 poses gradually, disengages protoxide of azote, effloresces, and yields 

 a residue of pure sulphate of ammonia. 



I have above stated that the alkalies increase the stability of the ni- 

 trosulphates ; this however takes place with the nitrosulphate of am- 

 monia only to a certain degree. The salt, mixed with concentrated 

 caustic ammonia, still decomposes very visibly, though much more 

 slowly than in pure water, and yields moreover the same products. 

 This decomposition agrees well with what we observe in passing a mix- 

 ture of two volumes of deutoxide of azote and one volume of sul- 

 phurous acid into a bell-glass containing liquid ammonia : the absorp- 

 tion is never in this case complete, as it is with the potash ; there is 

 invariably a gaseous residue of protoxide of azote ; and if the nitrosul- 

 phate of ammonia is obtained at the ordinary temperature, by the pro- 

 cess which I have indicated, this depends upon the much greater 

 rapidity of its production than of its decomposition. We see by this, 

 that it is possible for a body to be formed and to exist for a certain 

 time at the same temperature at which it is decomposed. 



The excessive mobility of the elements of the nitrosulphate of am- 

 monia, and the stability which the alkalies give them, made me think 

 it not impossible that this salt might present phaenomena of decompo- 



