IMIDOSULPHONATES (2ND. PAPEE). 201 



volume, we obtained a concentrated solution of the two-thirds normal 

 ammonium salt, the strength of which we determined by analysis. To 

 it we added enough ammonia to make it a little more alkaline than 

 the normal salt. It was then mixed with a slight excess of concen- 

 trated solution of strontium chloride and left to stand. Only a very 

 small quantity of precipitate formed and this remained for the most 

 part suspended in the solution. We therefore added excess of some- 

 what concentrated ammonia water which greatly increased the quantity 

 of the precipitate, but the whole had such an unpromising appearance 

 that we did not care to try to separate the salt for analysis, probably a 

 strontium ammonium salt. We placed the whole in a desiccator over 

 anhydrous potassium carbonate and left it there until it had nearly 

 evaporated to dryness. We now added water which left a white 

 opaque powder, the mother liquor smelling mildly of ammonia. 

 Analysis of the powder proved it to be normal strontium imidosulpho- 

 nate, with a slight quantity of ammonia in addition. Our calculation 

 is for a pure strontium salt with 5 J mois, water. The salt may, how- 

 ever, be regarded as having only 5 mois, water. We determined the 

 alkalinity of the salt and have expressed it as strontium, thus showing 

 it to be more than a third of the total strontium. The excess of base 

 may be regarded as consisting of ammonium, the presence of a little 

 of which was established. 



When a solution of the normal strontium salt with 12 mois. 

 of water is boiled, precipitation of sandy particles occurs. The 



