2Q4 EDWARD DIVERS AND TAMEMASA HAGA : 



Normal calcium imidosulphonate. — The true normal salt can be 

 prepared by stirring together the insoluble normal silver salt with its 

 equivalent of calcium chloride in solution, decanting from silver 

 chloride, and evaporating the solution in a desiccator till the new salt 

 crystallises out. It is only sparingly soluble in water, when once 

 separated from solution, .and forms rectangular prisms and tables, 

 stable in the air. It is strongly alkaline to litmus. Its composition is 

 expressed by Ca 3 (NS 2 6 ) 2 , 8H 2 0. 



Calc. Found. 



Calcium, 19.60 19.G0 



Sulphur. 20.92 21.06 



Berglund states that the normal calcium salt is also got from a 

 mixed solution of ammonium imidosulphonate, ammonia, and calcium 

 chloride. This mixture gives us no insoluble salt. 



Tivo-thirds normal calcium imidosulphonate. — This salt is obtained 

 by decomposing normal silver imidosulphonate by two-thirds of its 

 equivalent of calcium chloride and one-third of its equivalent, or for 

 safety just a very little less, of hydrochloric acid. The solution, 

 separated from silver chloride and evaporated in a desiccator very far, 

 becomes a mass of radiating prisms. Crushed and drained dry, the 

 salt is permanent in the air, at least for days. Its reaction is slightly 

 acid to litmus. Its formula is CaliNSA. 3H,0. 



Calc. Found. 



Calcium, 14.87 14.70 



Sulphur, 23.79 23.59 



Calcium sodium imidosulphonate, CaNaNSoOß, 3H 2 0, is described 

 in our first paper, and has been referred to on p. 20 o, as being 

 what we get by following Berglund's directions for preparing his 

 normal calcium salt. The mercury calcium salt will be found described 

 on p. 211. 



