Dr. Kane on the Compounds of Ammonia. . 7 



analogous to that for the yellow powder formed by the action of water on white 

 precipitate, if we write the sulphate of mercury as h^. so^ ; then there is 



Hg-. cl-\-2 ngo -{- ng nh^, and 



H^. SO4 + 2 H^-O + ng NHj. 



We shall have occasion, hereafter, to advert to this type of a remarkable class 

 of combinations. 



III. ACTION OF AMMONIA ON SULPHATE OF BLACK OXIDE OF MERCURY. 



When the sulphate of the black oxide of mercury is treated by cold or boiling 

 water no reaction occurs indicating the formation of a basic salt ; it would there- 

 fore appear as if there existed but one sulphate of the black oxide. 



When sulphate of the black oxide of mercury is treated by water of ammonia 

 there is obtained a dark grey powder, which, when heated, gives water, ammonia, 

 sulphurous acid, oxygen, and mercury. It is thus indicated to be a basic salt, 

 containing ammonia ; but great difficulty was found in tracing accurately the 

 proportions in which complete decomposition occurred. 



To determine the nature of this grey compound, the following method was 

 adopted : — A weighed portion of sulphate of black oxide of mercury, was treated 

 by an excess of water of ammonia, until the reaction appeared to be complete, 

 and a uniform dark grey powder was produced. It was then collected on a filter, 

 and the liquors, which contained but a mere trace of mercury, were mixed and 

 acidulated by muriatic acid, and precipitated by muriate of barytes. The sul- 

 phate of barytes was then collected and dried, and having been ignited, with its 

 filter, weighed, and the correction for ashes made. 



The results of five experiments of this kind are given in the subjoined table, 

 the details being omitted, in consequence of my not intending to use these results 

 as bases for induction, and therefore it not being necessary to specify the par- 

 ticulars of each case : 



