Dr. Kane on the Compounds of Ammonia. 17 



consider that to be the rational formula. These crystals are formed by the solu- 

 tion of Soubeiran's subnitrate in nitrate of ammonia, and the formula is 



(H^NOe + 2 Hg-O -f Hgkd) + (nH^O . NOj, 



which is equal to twice 



(nh.,. NOj-j- 2h^o). 



That such is its constitution will be clearly shown from the study of the body 

 next to be described. 



When Soubeiran's ammonia subnitrate is boiled in a strong solution of 

 nitrate of ammonia it is dissolved in considerable quantity, and the liquor being 

 filtered while hot, deposits, on cooling, small but very brilliant needles, which 

 after some time lose their lustre, and become dull and opaque, an appearance 

 which the salt, when rapidly formed from a very strong solution, occasionally 

 possesses from the commencement. This salt, after it has been once dried, can- 

 not be again brought into contact with water without decomposition ; its consti- 

 tuents are reproduced, the nitrate of ammonia dissolving, and Soubeiran's sub- 

 nitrate being left undissolved. These circumstances rendered a few analyses 

 sufficient for determining its composition. 



A. 6.061 grammes of this salt were diffused through water, and decomposed 

 by a current of sulphuretted hydrogen gas. The sulphuret of mercury was col- 

 lected on a filter, and having been carefullydried, weighed 4.187, corresponding 

 to 69-08 sulphuret and 59.60 mercury per cent. The liquor and washings, eva- 

 porated to dryness, in a water-bath, gave 2.173 of nitrate of ammonia, therefore 

 35.85 per cent. 



B. 5.973 of a quantity prepared at a different time were dissolved in 

 muriatic acid, and treated by sulphuretted hydrogen. The sulphuret was cau- 

 tiously dried until it ceased to lose weight, and amounted to 4.010, giving 67.13 

 sulphuret, and 57.99 mercury per cent. 



Hence there is 



Mercury, mean value = 58.79 



Nitric acid = 24.17 



Ammonia = 7.65 



If we divide these numbers by the atomic weights of the bodies, and reduce 

 them to a standard, we shall find that there are almost exactly three atoms of 

 nitric acid, three of ammonia, and four of mercury. 



VOL. XIX. D 



