318 PROCEEDINGS OF THE AMERICAN ACADEMY 



I. 1.5527 grm. of the salt, crystallized from water and dried by 



exposure to the air, lost over suljjhuric acid 0.0953 grm. H.,0. 



II. 1.0746 grm. of the salt, precipitated by alcohol and dried by 



exposure to the air, lost over sulphuric acid 0.0663 grm. HoO. 



III. 1.0502 grm. of the salt, precipitated by alcohol and dried by 



exposure to the air, lost over sulphuric acid 0.0G31 grm. H.fi. 



The salt dried over sulphuric acid gave, on analysis, the following 

 results : — 



I. 0.2769 grm. of the salt gave 0.1837 grm. BaSO^. 



11. 0.2052 grm. of the salt gave 0.1368 grm. BaSO^. 



III. 0.5470 grm. of the salt gave 0.3678 grm. BaSO^. 



IV. 0.4128 grm. of the salt gave 0.2079 grm. CO^ and 0.0354 grm. 



H2O. 

 V. 0.4988 grm. of the salt gave 0.2516 grm. CO^ and 0.0477 grm. 

 H2O. 

 VI. 0.2120 grm. of the salt gave 0.1128 grm. AgRr. 

 VII. 0.2684 grm. of the salt gave 0.1457 grm. AgBr. 



Calculated for 

 BaCiHBrO^ . HjO. I, II. in. IV. V. VI. VII. 



Ba 39.37 



C 13.77 



H 0.86 



Br 22.99 22.64 23.11 



We have made many unsuccessful attempts to prepare an acid ba- 

 rium salt. In every case, when the acid solution was precipitated 

 with alcohol, or evaporated in vacuo over sulphuric acid, we obtained 

 only the neutral salt. 



Potassic Mucoxyhromate, K^C^HBrO^ . HgO. — The potassium salt 

 was prepared from the barium salt by exact precipitation with potassic 

 carbonate, and evaporation of the solution thus obtained in vacuo. It 

 crystallized in well-formed rhombic plates, which were very soluble 

 even in cold water. On warming the solution, decomposition quickly 

 ensued. The air-dried salt lost nothing over sulphuric acid, turned 

 somewhat brown at 70°, but did not lose sensibly in weight until 

 heated to 100°. 



I. 0.4951 grm. of the air-dried salt lost, at 100°, 0.0344 grm. H^O, 

 and gave 0.2991 grm. K^SO^. 



