112 PROCEEDINGS OF THE AMERICAN ACADEMY. 



The analysis of this substance gave much trouble, because of the ease 

 with which it exploded, but the ditiiculties were overcome by mixing it 

 with a large amount of cupric oxide, and heating very carefullv. 



P ruperties of TrinitropJienijltartronic Ester. — It forms white fluffy- 

 needles in clusters like sheaves or even circles. Under the microscope 

 the crystals are seen to be slender prisms terminated by a single plane at 

 an oblique angle. Its melting point is 117°. It is easily soluble in 

 ethyl, or methyl alcohol, in fact the hot concentrated solution in ethvl- 

 alcohol is so strong that it solidifies nearly completely on cooling. It is 

 also easily soluble in ether, benzol, chloroform, or acetone; soluble in 

 glacial acetic acid; somewhat soluble in carbonic disulphide ; soluble with 

 difficulty in ligroine ; insoluble in cold water, slightly soluble with decom- 

 position in hot. forming a reddish solution. The three strong acids have 

 no apparent effect on it in the cold, but hot strong sulphuric aciJ decom- 

 poses it, giving a dark color and an evolution of gas. Alkalies give with 

 it at once dark blood-red solutions probably containing its salts, but these 

 decompose rapidly, turning dirty brown, and we have not succeeded in 

 isolating the salts themselves, or any definite compounds from their 

 decomposition products. 



Trin itrophenyJacett/ltartron I'c Ester, 

 C6H.,(NOo)3C(OCOCH3)(COOCoH5),. 



Acetylchloride dissolves trinitrophenyltartronic ester easily, but does 

 rot react with it either at ordinary' temperatures, or when heated on the 

 steam bath in open vessels. We accordingly proceeded as follows : 

 Three grams of trinitrophenyltartronic ester were heated with 15 to 20 c.c. 

 of acetylchloride in a sealed tube to 110° for five or six hours. Care was 

 taken that the temperature did not go too high, as at 140° a blackish 

 decomposition product was also formed, which made the purification of 

 the product more difficult. On evaporating off the excess of acetylchlo- 

 ride white crystals separated, which were purified by crystallization from 

 alcohol until they showed a constant melting point of 125°, when they 

 were dried in vacuo, and analyzed with the following result: — 



0.2201 gram of the substance gave 19.4 c.c. of nitrogen at a tempera- 

 ture of 24° and a pressure of 761.6 mm. 



Calculated for 

 C6HJ(NOJ)3COC2H3O^CO0CJH5),. Fonnd. 



Nitrogen 9.79 9.88 



Properties of Trinitrophenylacefyltnrtronic Ester. — It forms white flat 

 rather broad prisms, or perhaps they should be called tables, terminated 



