4 P. C. Ray — Dimercurammonium Nitrate. [No. 1, 



which we have regarded as NHg 2 CI + H 2 0, breaks up, according to Kane, 

 into nitrogen, ammonia, water, mercury, and calomel. The anhydrous 

 salt, NHg 2 CI, according to Weyl, breaks up into HgCl + Hg-rN. Our 

 results with the hydrated variety conform to Weyl's result with the 

 anhydrous salt. It would thus appear that there is no necessity for set- 

 ting up two distinct types of compounds, viz., (1) mercuroxy-ammonium , 

 and (2) dimercurammonium, for the salts supposed to belong to the former 

 class do not yield any appreciable ammonia as they are stated, by Kane, 

 to do. Therefore the salts regarded as mercuroxy-ammonium compounds may 

 very reasonably be looked upon as (hydrated) dimercurammonium salts, [cf. 

 Trans. Ghem. Soc, Vol. 81, (1902), pp. 645-46]. 



This conclusion is further corroborated by the corresponding bromine 

 compound, which behaves exactly like the chloride. But a stronger argu- 

 ment in favour of the non-oxylic constitution of this class of compounds 

 seems to be based upon a study of the dimercurammonium nitrate, which 

 I have prepared according to two distinct methods (see below). 



Dimercurammonium Nitrate. — By P. 0. Ray, D.Sc. 



Preliminary. — When dimercurammonium nitrite is treated with 

 halogen acid, nitrous fumes are evolved and a clear solution is obtained, 

 which on concentration yields the double salt, 2 HgCl 2 .NH 4 Cl, or 2 HgBr 2 

 NH 4 Br, as the case may be. [Vide Journ. Ghem. Soc, Trans,, Vol. 81 

 (1902), p. 648], The behaviour of nitric acid towards the nitrite, how- 

 ever, affords a marked contrast, giving rise to the formation of a prac- 

 tically insoluble compound. Here, the nitrite molecule evidently does not 

 undergo a complete "break-up" and the reaction seems to consist in the 

 replacement of the radical NO z by N0 3 , just as silver nitrite under similar 

 conditions is converted into silver nitrate. 



For making a comparative study, the so-called mercuroxy-ammo- 

 nium l nitrate was also prepared and its properties studied. 



Preparation. — To the pale yellow dimercurammonium nitrite strong 

 nitric acid is added from a pipette, till the evolution of nitrous fumes 

 ceases. After a time the clear supernatant acid liquid is decanted off and 

 the substance dried over sulphuric acid till the weight is constant. The 

 mother liquor on testing indicates the presence of traces of mercury, show- 

 ing that the compound is only very slightly soluble in nitric acid. 



I The nomenclature adopted is as given in the new Edition of Watts' Dictionary 

 of Chemistry. 



