OP ARTS AND SCIENCES. 377 



bromic acid was dissolved in cold fuming nitric acid, and the nearly 

 saturated solution allowed to stand for several days at ordinary tem- 

 peratures. When the mixture had completely solidified, the nitric 

 acid was expelled by geaitle heat, and the dry residue distilled from a 

 small retort. In order to obtain a perfectly pure product, the distil- 

 late was dissolved in water, neutralized with baric carbonate, and the 

 baric dibrommaleate precipitated by the addition of alcohol. The 

 barium salt was then converted into the sodium salt, and from this the 

 silver salt was made by precipitation with argentic nitrate. 



According to Bourgoin, dioxymaleic acid is formed by heating ar- 

 gentic dibrommaleate with water to 150°. On opening the tubes after 

 heating for five hours he found that carbonic dioxide escaped, that 

 argentic bromide had been formed, and that the liquid in the tubes 

 was distinctly acid. On the addition of argentic nitrate to this acid 

 solution carefully neutralized with ammouic hydrate he obtained a 

 white insoluble silver salt, which gave on ignition a residue closely 

 agreeing with the weight of metallic silver required by the formula 

 AgoC^H^O,;. He found the acid to be a white crystalline solid, which 

 was readily soluble in water and alcohol, and barely soluble in ether. 

 With the alkalies and alkaline earths it formed readily soluble salts, 

 and showed itself to be non-saturated in that it was capable of fixing hy- 

 drogen and bromine. Bourgoin gives, however, no analytical results 

 whatsoever except the one already mentioned. 



On following closely the directions of Bourgoin, I found that the 

 argentic dibrommaleate had been almost completely decomposed, and 

 that at least 95 per cent of the theoretical amount of argentic bromide 

 had been formed. The liquid in the tubes was strongly acid, but the 

 carbonic dioxide which escaped was by no means insignificant in quan- 

 tity. Although the aqueous solution gave a crystalline precipitate with 

 argentic nitrate after careful neutralization with ammouic hydrate, it 

 was thought advisable to distil the liquid with steam before preparing 

 salts for analysis, since it was found that the acid volatilized readily 

 under these conditions. The acid distillate was neutralized with calcic 

 carbonate, the silver salt precipitated by the addition of argentic 

 nitrate to the concentrated solution, and recrystallized from hot water. 

 The silver salt thus obtained closely resembled argentic acetate, and 

 its identity was established by analysis, 



I. 0.4677 grm. of the air-dried salt gave 0.5249 grm. AgBr. 

 II. 0.2263 grm. of the air-dried salt gave 0.1465 grm. Ag. 

 III. 0.2056 grm. of the salt dried over sulphuric acid gave 0.1082 grm. 

 CO^. 0.0330 grm. H2O, and 0.1327 grm. Ag. 



