368 PROCEEDINGS OF THE AMERICAN ACADEMY 



The reaction is then strictly analogous to that by which /? brom- 

 styrol may be made from phenyldibrompropionic acid : 



C 7 H 5 Br 3 3 = C 6 H 4 Br 2 + C0 2 + HBr. 



The aqueous solution left in the retort after distillation with steam 

 deposited on long standing a small quantity of a crystalline acid. The 

 quantity of this acid was so insignificant that we were able to iden- 

 tify it only after uniting the products obtained in many successive 

 preparations. Two determinations of the percentage of bromine 

 showed the acid to be the bromfurfuracrylic acid subsequently de- 

 scribed. Lack of material made it impossible to prove with precision 

 the identity of the two acids, and we can therefore only assert their 

 close resemblance. 



I. 0.1262 grm. substance gave 0.1091 grin. AgBr. 

 II. 0.1956 grm. substance gave 0.1700 grm. AgBr. 



Calculated for Found. 



C 7 II,Br0 3 . I. II. 



Br 36.86 36.79 36.99 



We have hitherto been unable to find other definite products of 

 the reaction. 



By the action of bromine upon bromfurfurbromethylen we could 

 obtain no products which invited further study. On the other hand, 

 alcoholic potassic hydrate gave us the corresponding acetylen deriva- 

 tive, although we have not yet isolated it in a pure condition. The 

 oil obtained as the direct product of the reaction contained much too 

 large a percentage of bromine, and prolonged action at a higher 

 temperature gave no more satisfactory results. That the oil con- 

 tained the acetylen derivative was readily shown by its behavior with 

 an ammoniacal solution of silver or copper. The silver compound 

 was white, the copper compound a greenish yellow. The latter was 

 made in larger quantity, carefully washed by decantation, and dried 

 over sulphuric acid. It then exploded violently by heat or on contact 

 with fuming nitric acid, and contained the required percentage of 

 copper. 



I. 0.6479 grm. substance gave by electrolysis 0.1748 grm. Cu. 

 II. 0.6178 grm. substance gave 0.1681 grm. Cu. 



Calculated for Found. 



[CgHjBrOJjCuj. I. II. 



Cu 27.16 26.98 27.20 



From the copper compound we attempted to prepare the bromfurfur- 

 acetylen in a pure condition. By decomposing with acid, extracting 



