SULPHATE OF BARYTA IN ACID SOLUTIONS. 



93 



On comparing the results contained in this table with those 

 able No. 2, it is observed that the formation of sulphate 

 of baryta is not facilitated by boiling. This fact was often 

 confirmed during the course of my experiments, by taking 

 the clear solutions which remained when the precipitate of 

 sulphate of baryta had subsided and bringing them to ebul- 

 lition, without in any case obtaining a precipitate. 



EMPLOYMENT OF SULPHURIC ACID INSTEAD OP SULPHATE OF 



POTASH. 



I thought it right to make the following series of experi- 

 ments, in order to ascertain that the non-formation of sulphate 

 of baryta, in a liquor rendered acid by nitric acid, was not 

 owing to a combination being formed between the sulphate 

 of potash and the nitric acid ; to attain this object, I poured 

 into each multiple volume of nitric acid a quantity of sulphu- 

 ric acid, equivalent to that contained in 3.34 grs. of sulphate 

 of potash, and the results obtained were identical with those 

 observed in Table No. 2 ; consequently no combination was 

 formed between the nitric acid and the sulphate of potash. 



TABLE No. 8. 



I also made several series of experiments, dissolving first the 

 nitrate of baryta in the nitric acid, and then pouring into it 

 the sulphate of potash ; but this mode of operating did not 



