92 PROCEEDINGS OF THE AMERICAN ACADEMY 



dimalonic compound is less stable toward nitric acid than the brom- 

 malouic compound, since the latter, after three hours' boiling with the 

 acid, had not gone further than the tartronic ester, while the former 

 usually underwent a total decomposition. On the other hand, the 

 nitrite of the dimalonic compound is not decomposed by melting, and 

 only slightly by heating with alcohol, and therefore in these two re- 

 spects is more stable than the nitrite of bromtrinitrophenylmalonic 

 ester. 



The nitrite of trinitrophenylenedimalonic ester shows acid proper- 

 ties. With an aqueous solution of acid sodic carbonate it gives no 

 action, and very little when alcohol is added, unless in very large 

 quantity, when a yellowish solution is formed ; with potassic carbonate 

 in aqueous solution there is no action, but on the addition of alcohol a 

 very strong yellowish brown color ; aqueous sodic hydrate gives a red- 

 dish solution, on the addition of alcohol an orange flame-colored solution, 

 entirely different in color from that given vv'ith the potassic carbonate ; 

 ammonic hydrate imparts a strong yellow coloration to the solution, 

 intensified on the addition of alcohol. Upon comparing the acidity of 

 this substance with that of the trinitrophenylenedimalonic ester, it 

 seems as if this latter substance were somewhat more acid than the 

 nitrite, since it gives a slight coloration with aqueous potassic carbon- 

 ate, and seems to act more easily with acid sodic carbonate and alco- 

 hol, but the difference between the two in this respect is certainly very 

 slight, which we should not have expected, as it seemed probable that 

 the introduction of the nitrous acid radical (ONO) would have in- 

 creased the ease with which the hydrogen in the other malouic ester 

 radical was removed. 



A solution of the sodium salt of the nitrite of trinitrophenylenedi- 

 malonic ester was made by adding one drop of sodic hydrate solution to 

 a large excess of the ester moistened with alcohol, and, after the action 

 had taken place, diluting with much water. Tlie solution thus ob- 

 tained was of the color of a solution of potassic dichromate, but much 

 less stronpjly colored than the solutions of the salts of any of the re- 

 lated substances. Its action with the various reagents was tried, and 

 the following characteristic precipitates observed ; — 



With barium salt, rather heavy yellow flocks. 



With morcurous or lead salts, heavy yellow flocks. 



With silver or copper salts, yellow flocks. 



Salts of calcium, sU'ontium, or magnesiimi gave only faint yellow pre- 

 cipitates, decidedly different from the heavy one produced by baric 

 chloride. 



