OF ARTS AND SCIENCES. 173 



dilute alcohol, melted at 89°. This gave on analysis a percentage of 

 bromine which was approximately that required by the formula 

 C.lI^Br.O,. 



0.1884 grm. substance gave 0.2897 grra. AgBr. 



Calculated for CiHoBr^O,. Found. 



Br 6G.12 65.45 



The formation of the tetrabromfurfuran could be avoided almost en- 

 tirely by the rapid addition of the bromine. Still, rather more than one 

 molecule of bromine was necessary for complete oxidation of the acid, 

 and the purification of the product was difficult. The ethereal extract 

 left on evaporation a viscous residue, which rarely solidified when 

 allowed to stand in vacuo over sulphuric acid. By extracting this 

 viscous residue with boiling water, we succeeded, however, in obtain- 

 ing a crystalline product which melted at 90-91°, but which gave on 

 analysis too low a percentage of bromine (I.). Since it seemed not 

 improbable that the substance contained mucobromic acid, we dissolved 

 it in a dilute solution of sodic carbonate, and extracted it from the 

 alkaline solution with ether ; but the percentage of bromine was unal- 

 tered (II.). By sublimation in a stream of carbonic dioxide, however. 

 we obtained a product which melted at 89-90°, and gave the required 

 percentage of bromine (III.). 



I. 0.1496 grm. substance gave 0.2295 grm. AgBr. 



II. 0.1981 grm. substance gave 0.2955 grm. AgBr. 



III. 0.1340 grm. substance gave 0.2089 grm. AgBr. 



Br 



This substance is readily soluble in alcohol, ether, chloroform, or 

 benzo), more sparingly soluble in ligroin. It is readily soluble in hot 

 water, more sparingly in cold, and crystallizes from aqueous solution 

 in small prisms which often form lattice-like aggregations. By oxida- 

 tion it yields mucobromic acid, and it must therefore be considered to 

 be dibrommaleic aldehyde. The difficulty of its preparation in quan- 

 tity made it impossible for us to study it more in detail at present, but 

 we hope to return to it at some future time. 



