364 • PROCEEDINGS OF THE AMERICAN ACADEMY 



tied, the existence of geometrically isomeric forms of its derivatives 

 seemed at the outset more thau prohable, and during the progress of 

 the investigations which for many years have been carried on in this 

 laboratory careful search had been made for such bodies, but hitherto 

 only the two isomeric dibromfurfuran tetrabromides of Hill and Harts- 

 horn * had been discovered. Since the discovery of the ^ dichlorpyro- 

 mucic acid, which we made toward the close of our work, we have 

 attempted to prepare the corresponding bromine derivative, but as yet 

 without success. The isolation of the body C 4 H 3 Br0 2 , which Hill 

 and Sanger f found among the products of the decomposition of 

 pyromucic tetrabromide by alkalies, certainly is an indication of the 

 previous existence of such an acid, although it is by no means clear in 

 what stage of the process the decomposition of the acid was effected, 

 nor how the decomposition product itself escaped further alteration. 

 Any detailed consideration of the geometrical structure of pyromucic 

 acid we' feel obliged to postpone until more facts bearing upon the 

 question are at our disposal. 



II. — ON CERTAIN DERIVATIVES OF FURFUR- 

 ACRYLIC ACID. 



By H. B. Gibson and C. F. Kahnweiler. < 



Presented May 28, 1889. 



The preparation of furfuracrylic acid was described by v. Baeyer t 

 1877. At that time, however, the investigation of the acid was 

 pushed in but one direction, and the successive steps by which it 

 could be converted into a pimelic acid were alone described in detail. 

 It seemed that a further study of the acid in other directions also 

 could hardly fail to yield interesting results. 



The ready decomposition of furfuracrylic acid by mineral acids 

 compelled us to relinquish the line of work we originally had pro- 

 posed to follow, and we consequently began an investigation into the 

 nature of this decomposition. The study of the action of hydrochloric 

 acid upon an alcoholic solution of furfuracrylic acid was just beginning 



* Berichte der deutsch. chem. Gesellsch., xviii. 450. 



t These Proceedings, xxi. 158. 



t Ber. d. deutsch. chem. Gesellsch., x. 355. 



