124 PROCEEDINGS OF THE AMERICAN ACADEMY 



namely, 



must take up water, 



X M 2 



OH 

 'OH 



R-cr 



X NH 2 



and then again split off water in a different way, 



/OH 



so that this reaction is not as simple as was formerly supposed. 



The different behavior of the silver and sodium salt of an acid- 

 amide seems to me to be cleared up by the work on acetacetic 

 ether,* without the very improbable assumption that the salts are 

 differently constituted, i. e. that tautomerism exists in this class 

 of compounds. 



Mesoxalic-acid-phenylhydrazone, from Mesoxanilidehydrate. 



The proof that the above compounds are in reality derivatives of 

 mesoxalic acid is the following. 



Mesoxanilidehydrate was dissolved in four molecules pure sodic 

 hydrate, and evaporated to dryness on a water bath. After taking 

 up with water, and extracting with ether (to get rid of aniline 

 split off), the aqueous solution was heated for 1£ hours longer, and 

 then again evaporated to dryness, f After acidifying with dilute 

 hydrochloric acid, whereby an evolution of carbon dioxide is no- 

 ticed, and adding phenylhydrazine hydrochloride, a voluminous 

 yellow precipitate results. It was purified by dissolving in dilute 



* Ann. Chem. (Liebig), CCLXVT. 135. 



t It is necessary to heat so long because mesoxanilidehydrate goes over 

 into mesoxalic acid with difficulty. In the first experiment the alkaline solu- 

 tion was evaporated only once on a water bath. On acidifying, and adding 

 phenylhydrazine hydrochloride, a substance separated out in yellow needles, 

 which, recrystallized from alcohol, melted with decomposition at 153°. 



The analysis gave results agreeing well with an intermediate product, 



C 6 H 5 N=C° H 



^C=NNHC 6 H 6 : 



HOCO 



