OP ARTS AND SCIENCES. 161 



I. 38.3346 grm. of a solution saturated at 20° gave 0.0462 grm. 

 BaSO,. 

 11. 38.3935 grm. of a solution saturated at 20° gave 0.0464 grm. 

 BaSO^. 



According to these determinations the aqueous solution of the acid 

 saturated at 20° contained the following percentages : — 



I. II. 



0.28 0.28 



Saric (38-Dibrompyromucate, Ba(C5HBr203)2 . 4 HjO. — The barium 

 salt we prepared by neutralizing a boiling aqueous solution of the acid 

 with baric carbonate. After recrystallization from boiling water, it 

 formed fine branching needles. The air-dried salt contained four 

 molecules of water, three of which it lost over sulphuric acid. 



I. 1.4800 grm. of air-dried salt lost 0.1117 grm. H^O over sulphuric 

 acid, and in addition 0.0324 grm. H^O at 110°. 

 II. 2.1113 grm. of the air-dried salt lost at 110° 0.2030 grm. HgO. 



I. 0.4109 grm. of the anhydrous salt gave on ignition with HjSO^ 

 0.1415 grm. BaSO,. 

 II. 0.7780 grm. of the anhydrous salt gave on ignition with IToSO^ 

 0.2666 grm. BaSO,. 



Calculated for Found. 



Ba(C5lIBr,03)2. I. 11. 



Ba 20.30 20.24 20.14 



The solubility of the salt in cold water we determined by precipi- 

 tating the saturated solution with sulphuric acid. 



I. 38.7621 grm. of a solution saturated at 16° gave 0.0132 grm. 

 BaSO,. 

 II. 36.2526 grm. of a solution saturated at 16° gave 0.0129 grm. 

 BaSO,. 



The aqueous solution saturated at 16° therefore contained the fol- 

 lowing percentages of the anhydrous salt : — 



I. II. 



0.10 0.10 



VOL. XXI. (X. S. XIII.) 11 



