IMIDOSULPHONATES (2ND. PAPER). 203 



Found. 



25.96 25.97 



6.69 



18.89 



Berglund got granular precipitates of a strontium, potassium salt 

 soon after mixing normal potassium imidosulphonate solution with 

 strontium chloride solution. Calculating from his results, we find the 

 salt was represented by the formula Sr 12 K 8 H(NS 2 6 ) 1I , loH 2 0, in close 

 agreement with the composition of his barium potassium precipitates, 

 as calculated by us. 



Calcium imidosulphonates. 



By mixing solutions of normal sodium imidosulphonate and of 

 calcium chloride, Berglund got what he described as the normal calcium 

 salt, while, by proceeding in the same way, we have never got but the 

 calcium sodium salt described in our first paper. Berglund's salt and 

 ours agree in the descriptions given of them by him and us respective- 

 ly, and they would have the same composition, if for the atom of 

 sodium in our salt we put half an atom of calcium. Now Berglund 

 estimated the calcium from the weight of the residue left by the 

 ignited salt, and so little difference would there be in the weight 

 of the residue by the presence of sodium in place of a third 

 of the calcium, that the percentage numbers would only vary 

 within the limits of error of an ordinary analysis. Possibly, therefore, 

 he mistook the mixed sulphates for pure calcium sulphate, but whether 

 that was the case or not, his normal calcium salt is like our calcium 

 sodium salt and unlike our normal calcium salt, which we describe for 

 the first time. 



