OF ARTS AND SCIENCES. 315 



XVI. 



CONTRIBUTIONS FROM THE CHEMICAL LABORATORY OF 



HARVARD COLLEGE. 



OX MUCOXYBROMIC AND MUCOXYCHLORIC ACIDS. 

 By Henry B. Hill and Arthur AV. Palmer. 



Presented February 9, 1887. 



The action of baric hydrate upon miicobromic acid was studied several 

 years ago by 0. R. Jackson and one of us.* It was found that muco- 

 bromic acid was decomposed by a large excess of baric hydrate with 

 the formation of a /? dibromacrylic and formic acids, while an essen- 

 tially different reaction ensued in a feebly alkaline solution. The 

 main product in this case was shown to be a dibasic acid containing 

 four atoms of carbon ; but it was not further studied. Somewhat 

 later, E. K. Stevens and one of us f found that mucophenoxybromic 

 acid was formed by an analogous reaction when mucobromic acid was 

 treated with potassic phenylate ; and the constitution of this acid was 

 established with little difficulty by its conversion into phenoxybrom- 

 maleic and phenoxybromacrylic acids. The great stability of the 

 latter acid in alkaline solution left no doubt that its structure was 

 represented by the formula 



CHBr 



II 



C - O . C.H, 



I 



COOH. 



While it was thus rendered probable that in the corresponding de- 

 compositions by baric hydrate an atom of bromine in the mucobromic 

 acid had been replaced by hydroxyl, and the empirical formula of the 

 product formed also warranted this conclusion, it was difficult to ob- 

 tain any definite experimental evidence in its support. The isomerism 



* These Proceedings, Vol. XVL p. 188. 

 t These Proceedings, Vol. XIX. p. 262. 



