214 PROCEEDINGS OP THE AMERICAN ACADEMY 



0.4G80 grm. of the air-dried salt gave 0.3561 grm. AgCl and 0.2009 

 grm. BaS0 4 . 



By drying over sulphuric acid the precipitated silver salt, we were 

 unable to obtain it with any more definite or constant percentages of 

 water. 



The lead salt is almost insoluble in water or in dilute acetic acid ; 

 but we have been unable as yet to obtain any results on analysis which 

 were wholly satisfactory. 



There can be no doubt that /3-sulpho-S-brompyromucic acid is de- 

 composed by bromine in aqueous solution according to the following 

 equations : — 



C 5 H 3 BrSO e + Br 2 = C 4 H 2 Br 2 S0 4 + C0 2 + HBr. 

 C 4 H 2 Br 2 S0 4 + Br 2 + 3 H 2 = C 4 H 4 S0 7 + 4 HBr. 



Action of Nitric Acid. 



The decomposition of /3-sulpho-S-brompyrornucic acid with nitric 

 acid we have followed qualitatively. We have been unable hitherto 

 to effect a replacement of the sulpho-group by the action of fuming 

 nitric acid, as we had so readily done with the 8-sulphonic acids. In 

 this case, whatever was the strength of the nitric acid, we could only 

 prove the formation of an acid which was identical in its behavior with 

 sulphofumaric acid. Not unfrequently, however, the oxidation had 

 gone further, and oxalic acid was also formed together with sulphuric 

 acid. 



We have made a few experiments concerning the action of fusing 

 potassic hydrate upon potassic /3-sulpho-S-brompyromucate, and have 

 as yet been able to prove the formation of nothing but oxalic acid. 

 While it is doubtful whether any other product but oxalic acid is nor- 

 mally formed, we shall study the reaction further, as well as the action 

 of fusing sodic formiate. 



/3-SuLPHOPYROMUCIC AdD. 



The ammoniacal solution /3-sulpho-S-brompyromucic acid is reduced 

 without difficulty by zinc dust. A strongly ammoniacal solution of 



