338 PROCEEDINGS OF THE AMERICAN ACADEMY 



products formed from them by the action of aqueous bromine. The 

 two central carbon atoms are therefore alone concerned in the trans- 

 formation of mucobromic and mucochloric acids into the corresponding 

 oxy -acids ; and the first steps at least in this change must be the 

 replacement of one of the halogen atoms by hydroxyl. 



Since potassic phenylate acts upon mucobromic acid with the forma- 

 tion of mucophenoxybromic acid, whose constitution has been shown 

 to be* 



1° 



CBr 



II 

 C_0-C,H, 



I 

 COOH, 



it could safely be assumed that in the analogous reaction with baric 

 hydrate the a halogen atom would also be first replaced. The forma- 

 tion of dibromchlor aldehyde, 



ici 



by the action of bromine upon mucoxychloric acid, proves that this 

 assumption is correct, since the /8 chlorine atom has here retained its 

 place. It follows, therefore, that the mucoxybromic and mucoxy- 

 chloric acids are either hydroxyl acids formed by the replacement of 

 the a halogen atoms by hydroxyl, 



pH pH 



I I 

 CBr CCl 



II II 



C — OH C — OH 



I I 



COOH COOH, 



* These Proceedings, Voh XIX. p. 268. 



