OP ARTS AND SCIENCES. 293 



I. n. 



1.90 1.90 



These results agree exactly with those obtained by Hill and Palmer 

 for /3-sulphopyromucic acid, and the relative position of the sulpho 

 group is thus established with precision. 



Action of Bromine. 



/8-sulpho-S-chlorpyromucic acid is readily oxidized in aqueous solu- 

 tion by broraine, carbonic dioxide is liberated, but little or no sulphuric 

 acid IS formed even when the action is long continued at 100°. With 

 an excess of bromine, an acid is formed which is undoubtedly identical 

 with the sulphofumaric acid described by Hill and Palmer,* while a 

 derivative of furfuran-^-sulphonic acid is formed in nearly theoreti- 

 cal quantity, if but a single molecule of bromine is added. For its 

 preparation we passed into a cold aqueous solution of baric /3-sulpho-S- 

 chlorpyromucate the vapor of the calculated weight of bromine by 

 means of a current of air, and evaporated to a small volume the feebly 

 acid solution thus obtained. The barium salt of the aa-chlorbrom- 

 furfuran-/3-sulphonic acid which was thus obtained could then be 

 purified by recrystallization. By evaporation in desiccator the free 

 acid was obtained as a waxy deliquescent mass, which showed but slight 

 indications of crystalline structure. 



Baric aa-Chlorbromfurfuran-fi-Sulpkonate, Ba(C4HClBrS04)2 . HgO. 



This salt is readily soluble in hot water, less soluble in cold water, 

 and separates in pearly plates when its hot solution is quickly cooled. 

 A cold solution by spontaneous evaporation deposits this salt in clusters 

 of radiating needles. 



I. 0.8479 grm. air-dried salt gave 0.2936 grm. BaSO^. 

 n. 5210 grm. air-dried salt gave 0.1797 grm. BaSOi. 

 HI. 1.1406 grm. air-dried salt lost at 120° 0.0314 grm. HgO. 

 IV. 1.6890 grm. air-dried salt lost at 138° 0.0491 grm. HgO. 



Calculated for Found. 



Ba(C«UClBrS0«)2 . HjO. I. II. HI. IV. 



Ba 20.27' 20.35 20.28 



H2O 2.66 2.75 2.90 



I. 0.7017 grm. salt dried at 138° gave 0.2496 grm. BaSO^. 



II. 0.9112 grm. salt dried at 138° gave 0.3259 grm. BaSOi. 



III. 0.7824 grm. salt dried at 130° gave 0.2795 grm. BaSOi. 



* These Proceedings, xxiii. 211. 



