21Q EDWARD DIVERS AND TAMEMASA HAGA ; 



After adding the mercuric sodium imidosulphonate to it, the mixture 

 is well stirred, so as to insure the entrance into solution and chemical 

 reaction of all basic mercurous nitrate, and until the mother liquor has 

 just lost its acidity. The precipitate is white and settles quickly, 

 and can be freely washed. When dry its colour is dull. It 

 contains nearly all (-^-) of the mercury of the nitrate, but only 

 -j- of the mercuric radical, and even only -|- of the imidosulphonic 

 radical, its mother-liquor being very rich in imidosulphonate. This 

 condition of the mother-liquor gives assurance that no mercurous 

 nitrate can be in the precipitate and, in accordance with this, none 

 can be found. Testing, however, for nitrate is interfered with by the 

 presence of imidosulphonate. That the dry imidosulphonate does not 

 effervesce in the least with cold strong sulphuric acid is best proof to 

 ourselves of its absence (6 77). Both precipitate and mother-liquor 

 contain no sulphate. 



In the analysis, the two mercury radicals were estimated by 

 dissolving the salt in dilute nitric acid, diluting the solution, precipi- 

 tating mercurous chloride by dilute hydrochloric acid, and from the 

 filtrate precipitating mercuric sulphide. After the salt has been hy- 

 drolysed in a sealed tube by hydrochloric acid, for sulphur estimation, 

 the mercuric radical is found increased in quantity at the expense of 

 the mercurous radical, and the oxygen in the air sealed up in the tube 

 is shown, by the lessened pressure in the tube, to have been absorbed, 

 and to have given rise to the increase of mercuric radical (see the 



