12 Dr. Kane on the Compounds of Ammonia. 



By the action of water on the crystallized pernitrate it is resolved into yellow 

 sub-pemitrate and an acid-reacting salt, which, when evaporated, yields, as was 

 already mentioned, the same crystallizable nitrate, whilst the excess of acid passes 

 off. There takes place, therefore, a division of the mercury into two portions, one of 

 which passes into solution, whilst the other is left in the insoluble yellow powder. 

 The salt in solution does not appear to crystallize, but to give, on concentration, 

 nitric acid and the crystallized basic salt of Mitscherlich. The proportion of 

 mercury which remains in the solution approximated, in my trials, to one-third 

 of that precipitated, and the action of water may be explained by the following 

 formula : 



2(N03-f 2Hg-o-i-2Ho) =: Iho.nOj-I-Sh^oJ + J H^O.NOs -f 3 Hd J 

 The crystalline pernitrate being considered as a double salt, which is decomposed 

 by water into its constituents. It may evidently be likewise considered as a 

 simple salt, the sum of the number of atoms of hydrogen and mercury remaining 

 still four, but capable of indefinite replacement within that limit. 



The proportions of mercury and nitric acid in solution, after the precipitation 

 of the yellow basic salt by water, must be quite definite, and should, if isolated, 

 produce a salt h^o . nOj. ho -\- 2 ho, corresponding to the ordinary nitrates of 

 copper and bismuth, but which may be so easily decomposed as to be uncrystal- 

 lizable. Moreover, if we look to the very general tendency to the formation of 

 bodies containing four equivalents of mercury, it will appear not impossible but 

 that a type of basic nitrates Hgo.vio^.iigo-\-2ngo may really exist, and on 

 which Grouvelle may have happened to alight, although I could not, even after 

 many trials, succeed in preparing it. 



Thus there should be a series of salts : 



Hgo . NO5 . HO -[- 2 HO . uncrystallizable. 



Hg-o. NO5 . H^o -j- 2ho . ordinary salt. 



Bgo . NOj . HO -{- 2 H^o . yellow basic salt. 



wgo . NO3 . H^o -\- 2h^o . Grouvelle's basic salt, 

 and also 



Hgo . NO5. H^o 4" 4 H^o . 'red basic salt. 



V. OF THE AMMONIA SUB-PERNITRATES OF MERCURY. 



It has been long known, that, by adding water of ammonia to a solution of 

 pernitrate of mercury, there is obtained a fine white powder, which has been 



