OF ARTS AND SCIENCES. 279 



the further study of this reaction, in which undoubtedly the aniline 

 acted on the acetacetic ester radical as well as on the bromine in the 

 benzol ring. That this bromine had been removed we proved by de- 

 tecting aniline bromide among the products of the reaction. 



Sodium Salt, C H 2 Br(NO 2 ) 2 CH 3 COCNaCOOC 2 H 5 . 



In the earlier portions of our work on the bromdinitrophenylacet- 

 acetic ester and allied bodies tbe determination of the composition of 

 the salts was of the greatest importance, as this was the only ex- 

 perimental method which we had found for deciding between the 

 formulas, 



I. C (; H,Br ( N0 2 ) 2 CH,CO CH COOGH., 

 II. C HI]] ND 2 ) 2 CH 8 COCCOOC 2 H 3 . 



This, at present, is no longer the case, as the discovery of acetylen- 

 tetracarbonic ester or tartronic acid as a secondary product in the for- 

 mation of the corresponding malonic compounds can be explained 

 only if a formula similar to I. is adopted, and the easy conversion of 

 bromdi- (or tri-) nitrophenylmalonic ester into the corresponding toluol 

 compound also could hardly be brought into harmony with a formula 

 like II. No similar proof has been applied to the acetacetic com- 

 pound, it is true: but when the close resemblance between this and 

 the malonic compounds is considered, there can be no doubt that they 

 are similarly constituted. The composition of the sodium salt there- 

 fore becomes of secondary importance, and this is fortunate, as we 

 have not succeeded in preparing it in a state of purity sufficient to 

 decide between the salts derived from formulas I. and II., although 

 our analyses leave no doubt as to its composition, if the first formula 

 i> adopted as correct. 



The salt was prepared by adding to a solution of the bromdiui- 

 trophenylacetacetic ester in absolute alcohol a solution of sodic hy- 

 drate or ethylate also in absolute alcohol, taking care that the ester 

 was in decided excess. The deep red alcoholic solution thus obtained 

 was evaporated rapidly to dryness in a narrow beaker sunk throughout 

 its whole height in a water bath, some ether having been added pre- 

 viously in order that its vapor might protect the solution from the 

 carbonic dioxide of the air until the alcohol began to boil. The 

 excess of ester was washed out of the dry residue with benzol, and 

 the salt dried at 100°, and analyzed with the following results : — 



I. 0.2102 gr. of the salt gave after treatment with sulphuric ;i 

 0.0361 gr. of sodic sulphate. 



