20$ EDWARD DIVERS AND TAMEMASA tTAGA ; 



enters the salt, displacing half the oxylic mercury. For we then find 



/ N(S0 3 HgO) 2 Hg 

 that we puss abruptly from HN(SO,HgO).,Hg to Hg< 



x N(S0 3 Na) 2 



Exp. I — To excess of very dilute mercuric nitrate (necessarily 

 acid) was added a very dilute solution (I in 50) of mercury sodium 

 imidosulphonate. Almost at once precipitation began, first as a diffused 

 opacity, soon as a dense crystalloidal deposit, leaving the solution quite 

 bright. The precipitate, washed by décantation with much water, 

 was dried on a tile. It and its fresh mother-liquor were free from 

 sulphate. Composition: — mercury, 73.70 °/o5 sulphur, 7.98 °/o5 sodium 

 0.08 %. 



Exp. II. — Mercuric nitrate solution, 250ccs, containing, 6 grams 

 mercuric oxide which had been dissolved in nitric acid one-sixth more 

 in quantity than that equivalent to it; 250ccs. of a solution containing 

 4 grams of mercury sodium imidosulphonate: these solutions mixed 

 very soon gave a soft, voluminous, crystalline precipitate which 

 readily settled. After decanting its mother-liquor, it was washed 

 once with dilute nitric acid and then with water repeatedly. Drained 

 dry on a tile, it weighed (>.j> grams, or four-fifths of the calculated 

 quantity. It was free from sulphate, as was also its mother-liquor. 

 Composition: — mercury, 73.44 °/oJ sulphur, 7.94 °/ ; sodium 0.08 °/o- 



Exp. III.— Dissolved 2.8 grams mercury potassium imidosulpho- 

 nate in 250ccs. water, and added it to 3 grams of concentrated 

 mercuric nitrate solution containing almost 1.5 grams of mercury as 

 nitrate. A crystalline precipitate at once formed; after a few moments 

 active stirring, the precipitate was allowed to settle and the bright 

 mother-liquor was decanted into another vessel containing 4.5 grams 

 more of the mercuric nitrate solution. A second precipitate was thus 

 obtained : both were washed by décantation and drained on tiles. 

 The first weighed 2 grains; the second 1.5 grams: by calculation each 



