16 Dr. Kane on the Compounds of Ammonia. 



be no doubt but that the true formula for Soubelran's subnitrate is as follows : 

 H^o . NO5 + 2h^o + Hg-Ac?, which gives 



4Hg- = 405.60 81.13 



499.88 100.00 



This compound resembles those already described containing chlorine and 

 sulphuric acid. 



By using strong nitrate of mercury, and a considerable excess of a strong 

 solution of ammonia, I have on two occasions obtained a yellowish white precipi- 

 tate, yielding between 84 and 85 per cent, of mercury, and containing nitric 

 acid and ammonia in the proportions of one equivalent of each. I have not, 

 however, discovered the circumstances under which this third modification may 

 be generated at will, for in trying often to form it, sometimes by hot liquors, at 

 other times using the solutions cold, I have obtained the substances previously de- 

 scribed, or else mixtures of them. The existence, however, of a yellowish white 

 powder containing more mercury than either, is certain, and I consider its formula 

 to be probably 



(h^O . NO5 -f 4 H^O + H^Arf), 



I shall not, however, dwell upon it more ; the relation which it holds to the red 

 sub-pernitrate is quite evident. 



The Crystalline Ammonia Subnitrate. — Mitscherllch had observed that if 

 the ammonia subnitrate of mercury be boiled with an excess of ammonia, and 

 nitrate of ammonia be added, a portion of the powder dissolves, and the liquor, 

 when it cools, yields, according as the excess of ammonia passes off, small crystal- 

 line plates of a pale yellow colour. I have verified this observation, but I did not 

 analyze those plates, because I could form but a very small quantity of them ; 

 and having found in all cases that Mitscherlich's analyses were remarkably 

 good, I considered that in the case of these crystals, which I found great diffi- 

 culty in preparing, I might rely upon his accuracy. He found these crystals to 

 be NH3.N05-t-2Hg-o. But while I believe the numbers to be true, I do not 



