1Ö8 



Divers and haga. 



The- preparation, (a), was precipitated from three molecules of mercuric 

 nitrate by two of imidosulphonate, while (h) was got by adding sodium 

 hydroxide to the decanted mofher-liquor of (a). The preparation, 

 (c), was precipitated from two molecules (3f nitrate by one molecule of 

 imidosulphonate, and (d) was formed in a non-acid mother-liquor. 

 All preparations, as well as their mother-liquors, were free from 

 sidphate. 



The formation of oxymercuric sodium imidosulphonate is ex- 

 pressed by the equation : — 



4Hg(N03)2 + 2NaN(S03Na)2-|-20H2=Hg(OHgS03)2NHgN(S03Na)2 + 



4NaNÜ3+4HN03. 



This reaction is noticeable for being one in which sodium is withheld 

 in the precipitate from nitric acid ; but, if imidosulphonic acid be re- 

 garded as a weaker acid than nitric acid, the precipitation of potassium 

 nitrate by tartaric acid or perchloric acid is quite as remarkable, while 

 if, as is most probable, it is like sulphuric acid, then the retention of 

 sodium from the nitric acid is only natural. It is hardly noticeable 

 for the precipitation of a b;isic salt \v\t\\ production of nitric acid, since 

 similar reactions are connnon with oxygenous mercuric salts. 



In its constitution, as regards the oxylic mercury, oxymercuric 

 sodium imido8ul})honate resembles oxymercuric sulphate and oxymer- 

 curic sulphite, as the following • formula display (J. Coll. Sei., t, 

 101):— 



Imidosulphonate (NaO'SOolg iN-Hg-NKSOs-O-Hg-O), :Hg 



Sulphate HgilO-Hg-ü-Süg-ü-Hg-O)^ :Hg 



Sulphite Hg:tSÜ2-0-Hg-ü)2:Hg 



Constitution, of the Mercinif Jmidosulplwnates. 

 From the widely established character of the relation between 



