376 PROCEEDINGS OF THE AMERICAN ACADEMY 



III. ON THE SO CALLED DIOXYMALEIC ACID. 



By W. S. Hendrixson. 



Presented May 28, 1889. 



Several years ago Bourgoin * announced the discovery of two new 

 acids which he had obtained by replacing the bromine of brommaleic 

 and dibrommaleic acid by hydroxy!, and which he therefore called oxy- 

 maleic and dioxymaleic acid. Although the experimental evidence as 

 to the existence of these acids was very slight, and their assumed struc- 

 ture wholly anomalous, they soon found place in many text-books. 



In 1886, at the suggestion of Fittig, the work of Bourgoin upon 

 oxymaleic acid was repeated by Scherks,t who found that his state- 

 ments were without foundation, and that brommaleic acid in aqueous 

 solution was not in the least attacked by argentic oxide, even at 100°. 

 Scherks further concluded that Bourgoin's statements concerning his 

 dioxymaleic acid must also be incorrect, because the dibrommaleic acid 

 which he used he claimed to have made from his tribromsuccinic acid, 

 an acid which could not be formed under the given conditions, as shown 

 by Fittig and Petri,t or if formed would at once be decomposed into 

 dibromacrylic acid and carbonic dioxide. This conclusion of Scherks 

 seems hardly justified by Bourgoin's statements. The dibrommaleic 

 acid which he used undoubtedly was made by the action of aqueous 

 bromine upon succinic acid, and, while his material may have been far 

 from pure, the question of its identity is in no way affected by his erro- 

 neous assumption that it had been formed by the decomposition of 

 tribromsuccinic acid. In any case the subject seemed to demand a 

 more careful investigation. At the suggestion of Prof. H. B. Hill, 

 I have, therefore, repeated Bourgoin's work upon dioxymaleic acid, 

 and find that decomposition is in this case readily effected, but that 

 the product formed is not dioxymaleic acid. 



The dibrommaleic acid needed for this investigation was made by 

 the oxidation of mucobromic acid with cold fuming nitric acid, a 

 method which had already been found in this laboratory to be much 

 more advantageous than the methods previously described. Muco- 



* Bull, de la Soc. Chim., xix. 482 ; xxii. 443. 



t Ann. d. Chem. u. Pharm., ccvii. 223. J Ibid., cxcv. 70. 



