260 PROCEEDINGS OP THE AMERICAN ACADEMY 



10 grs. of tribromtrinitrobenzol, treated as described above with 10.6 

 grs. of malonic ester, gave 6.4 grs. of bromtriiiitrophenylmalonic ester. 

 Ttie amount required by theory, if all the tribromtrinitrobenzol had 

 been converted into bromtrinitrophenylmalonic ester, is 10 grs.; there- 

 fore the yield is 64 per cent of the theoretical. The average yield 

 was between 50 and 60 per cent of the theoretical. 



Proper-ties. — The bromtrinitrophenylmalonic ester crystallizes in 

 white slender needles arranged in radiating groups, which, when ex- 

 amined with the microscope, are seen to be flat needles, or long plates 

 terminated by one plane, or, as commonly, by two at an obtuse angle 

 to each other. The crystals seem to belong to the monoclinic system^ 

 The melting point is 104° to 105°, and if heated to 160° the substance 

 becomes dark red, and gives off gas. It is essentially insoluble in 

 cold water, very slightly soluble in hot ; insoluble in ligroine ; slightly 

 soluble in ether ; not very soluble in cold, freely in hot ethyl or 

 methyl alcohol ; freely in benzol, carbonic disulphide, or glacial acetic 

 acid ; very freely in chloroform or acetone. Hot alcohol is the best 

 solvent for it. Strong hydrochloric acid has no action upon it, even 

 when the substances are warmed together in open vessels ; it is prob- 

 able, however, that in sealed tubes the same decomposition would take 

 place as that observed with the corresponding dinitro body. Strong 

 sulphuric acid dissolves a little in the cold, more when hot, forming a 

 colorless solution. Strong nitric acid has little or no action in the 

 cold, but, if warmed with it, converts it into an intensely red viscous 

 substance swimming in the red acid liquid, which by further action of 

 strong nitric acid becomes solid and crystalline. A fuller discussion 

 of the action of strong nitric acid and that of dilute sulphuric acid will 

 be found later in this paper. 



As was to be expected from the position of one of its hydrogen 

 atoms on a carbon surrounded by two carboxylester radicals and a 

 trinitrophenyl group, the substance possesses marked acid properties. 

 Sodic hydrate in excess gives only a pale red color with the solid 

 ester, owing to the very slight solubility of the sodium salt in sodic 

 hydrate, but upon adding water the coloration increases, and the addi- 

 tion of a few drops of alcohol produces a very dark red solution. 

 Potassic carbonate in aqueous solu^tion gives a slight red color, on the 

 addition of a little alcohol a dark red solution ; acid sodic carbonate 

 acts in much the same way, but the color produced by the aqueous 

 solution is paler than that given with potassic carbonate. Amnionic 

 hydrate gives a red color at once, but this cannot be obtained free 

 from ammonia by evaporation on the water bath, or by using an excess 



