210 PROCEEDINGS OF THE AMERICAN ACADEMY 



III. 0.4347 grm. of the salt dried at 1 15° gave, on heatiug with HN0 3 , 



0.1684 grm. AgBr and 0.2082 grm. BaS0 4 . 

 IV.. 0.5100 grm. of the salt dried at 115° gave, on heating with HN0 3 , 



0.1980 grm. AgBr. 



IV. 



16.52 



Potassic fi-Sulpho-b-brompyromucate, KoC^HBrSO,;. — The potas- 

 sium salt is very soluble in cold water, and crystallizes in thick rhombic 

 plates which are anhydrous. 



I. 0.4510 grm. of the salt gave 0.2247 grm. K,S0 4 . 

 II. 0.5020 grm. of the salt gave 0.2530 grm. K 2 S0 4 . 



Calculated for Found. 



K,C 5 IIBrSO<j. I. II. 



K 22.52 22.37 22.62 



Action of Bromine. 



Bromine in aqueous solution acts with readiness upon /3-sulpho-8- 

 brompyromucic acid or its salts. The products vary with the conditions 

 chosen. If one molecule of bromine is slowly added to a cold aqueous 

 solution of the barium salt, carbonic dioxide is evolved and baric di- 

 bromfurfuran sulphonate is formed together with baric bromide. This 

 reaction is obviously identical with that noticed by Hill and Harts- 

 horn * in the decomposition of 8-brompyromucic acid in alkaline solu- 

 tion by bromine in which aa-dibromfurfuran is formed. If the baric 

 /3-sulpho-S-brompyromucate is suspended in a little water, and bromine 

 slowly added, the salt at first dissolves and soon after the baric dibrom- 

 furfuran sulphonate crystallizes out. From a more dilute solution the 

 salt can readily be obtained by evaporation. In the latter case, the 

 solution is but feebly acid and the yield nearly quantitative. 



Baric aa-Dibromfurfuran-fi-sulphonate, Ba(C 4 HBr„S0 4 )., . H.,0. — 

 This salt is quite readily soluble in hot water, more sparingly in cold 

 water, and crystallizes in pearly scales or plates. 



I. 0.8179 grm. of the air-dried salt lost, at 135°, 0.0204 grm. H 2 0. 

 II. 0.8833 grm. of the air-dried salt lost, at 125°, 0.0224 grm. H 2 0. 



* Berichte d. deutsch. chem. Gesellsch., xviii. 44b. 



