152 PROCEEDINGS OP THE AMERICAN ACADEMY 



disulpliide or ligroin. It was readily soluble in hot water, but spar- 

 ingly soluble in cold water. 



0.6771 grm. substance gave 46.5 c.c, of moist nitrogen at 22.5'^ and 

 under a pressure of 741 mm. 



Calculated for CsUoBrOoNH,. Found. 



N 7.37 7.74 



/3-monobrompyromucic acid appears to form no stable addition pro- 

 duct with bromine. When exposed to the vapors of bromine for two 

 days, we found that it had gained but 30 per cent of its weight, while 

 a gain of 168 per cent was required for the formation of a tetra- 

 bromide. This slight gain in weight and the abundant evolution of 

 hydrobromic acid pointed to the formation of a dibrompyromucic acid, 

 for which a gain of 41 per cent was required. The product gave little 

 evidence of decomposition when boiled with water, and was almost 

 wholly soluble in a dilute solution of sodic carbonate. When recrys- 

 tallized once from glacial acetic acid it melted at 165-166°, and 

 possessed the characteristic properties of /3S-dibrompyromucic acid. 

 Bromine at ordinary temperatures had therefore replaced one atom 

 of hydrogen by bromine. 



Action of Bromine and Water. 



When /3-monobrompyromucic acid is treated with bromine in aque- 

 ous solution it is rapidly oxidized, and products are formed which are 

 apparently analogous to those formed from pyromucic acid under simi- 

 lar conditions. One or two molecules of bromine were readily taken up 

 in the cold. In either case, the clear aqueous solution, when extracted 

 with ether, yielded viscous oily products which showed no signs of crys- 

 tallization after standing for days in vacuo over sulphuric acid. The 

 extremely uninviting character of these substances made us unwilling 

 to spend more time upon them at present, more especially since we 

 found that mucobromic acid was formed when three molecules of 

 bromine were employed. The reaction in this case required heat for 

 its completion, and fi-om the concentrated solution mucobromic acid 

 (melting-point 120-121'^) crystallized on cooling. Since it is probable 

 that the aldehyde acid with one bromine atom corresponding to muco- 

 bromic acid is formed by the action of two molecules of bromine, we 

 hope in the future to study the reaction further. 



