224 CONVERSION OF THE SULPHATES OF THE ALKALIES. 



The carbonates of the alkalies can also be formed by first 

 forming these organic salts from the sulphates, evaporating 

 the solution to dryness and burning the residue; in fact, I fre- 

 quently find it more convenient to convert the sulphates of the 

 alkalies into their carbonates by this last instead of the first 

 process. And finally I would remark that where magnesia 

 is present with the sulphates this is also separated from the 

 alkalies. 



