LMIDOSULPHOXATES (2ND. PAPER). 209 



would have weighed 2.9 grams, had none remained dissolved, according 

 to the equations, — 



1 . HgN,(S0 3 ) 4 K 4 + 2Hg(NO s ), + l 2H 2 



=HN(S0 8 ) 2 Hg 3 2 +2KNO s +2HNO s +HN(S0 8 ) 2 K 2 ; 



2. HN(S0 8 ) 2 K 2 + 3Hg(N0 8 ) 2 + 2H 2 = HN(S0 8 ) 2 Hg 8 2 +2KN0 8 +4HN0 8 , 



The first precipitate contained — mercury, 72.85°/oj sulphur, 8.03°/ ; 

 potassium, 0.3°/ ; the second contained — mercury, 72.6 1°/ ; sulphur, 

 8.11°/ ; potassium, 0.38%. From which it is seen that in no case is 

 alkali metal absent; that the quantity present is markedly greater in 

 the case of potassium than in that of sodium; and that the potassium 

 is a little more in quantity in the presence of more nitric acid (the 

 same was found true of sodium in the earlier experiments. This 

 apparently strange result is quite natural, for nitric acid dissolves 

 mercuric imidosulphonate, without having any action upon the two- 

 thirds normal potassium or sodium salt. 



The results of the above experiments, together with those 

 described in our first paper, can, Ave think, leave no doubt that the 

 basic mercuric salt has the composition, HN(S0 3 HgO).>fIg, the per- 

 centage numbers for which are — -mercury, 74.35; sulphur, 7.93. 

 For, the potassium present in the precipitates of Exp. Ill above, fully 

 accounts for the slight deficiency of the mercury in them. As already 

 stated, it is probable that Berglund got his analytical results as a, 

 consequence of the presence of unobserved potassium. 



Mercury ammonium imidosulphonate. — From the mercury calcium 

 salt, described on p. 211, we tried to prepare the mercury am- 

 monium salt by decomposing it, with just enough ammonium acid 

 carbonate. Success seemed to follow, but in ;i very few minutes a 

 secondary decomposition set in. That is to say, at first calcium 

 carbonate alone precipitated with effervescence of carbon dioxide, which 



