IMIDOSULPHONATES (2ND. PAPER). 211 



is right, HgNo(S0 3 ) 4 Na 4 ,5H 2 0. We have also found now that the 



salt, left in a vacuum over sulphuric acid for weeks, loses all its water, 



and not merely two-thirds of if, as stated in our first paper. Berglund 



dried his salt at; 100? 



Oxijmereuric sodium imidosulphonate. — No knowledge of such a salt 



as the basic mercury sodium salt, which we have described in our first 



paper, was possessed by Berglund, or of a corresponding potassium salt. 



But it is interesting to find that he could not get the mercury silver salt, 



but only a mercury silver potassium salt, by mixing normal mercury 



potassium imidosulphonate with silver nitrate even in excess. His 



/ N(S0 3 Ag) 2 

 formula for this salt, llg/ , 3H 9 0, is quite analogous to 



\N(S0 3 K), 



/ N(S0 3 HgO) 2 Hg 

 ours for the basic mercury sodium salt, I Ig/ , oILO. 



' \N(SO s Na) 2 



The water of crystallisation in this mercury salt was found by us to 

 be too low for the 4H 2 adopted by us, and we would now write it 

 3H 2 0j which agrees slightly better with the results of analysis. 



Mercury calcium, imidosulphonate. — Berglund obtained and de- 

 scribed mercury barium, mercury strontium, and mercury magnesium 

 imidosulphonates, but failed to get the mercury calcium salt, because of 

 its free solubility in water. We have prepared it by dissolving mercuric 

 oxide in a warm solution of two-thirds normal calcium imidosulpho- 

 nate, filtering, evaporating, crystallising, and, finally, recrystallising 

 from water. It forms small brilliant prisms. 



('alt-. Pound. 



Mercury, 25.90 25.92 



Calcium, 10.36 10.20 



Sulphur, 16.58 16.61 



A compound of this salt with mercuric chloride, which can be for- 

 mulated as CUigo(NSoO t; Ca) 3 , 12H..O, and, therefore, be compared with 



