74 PROCEEDINGS OP THE AMERICAN ACADEMY 



VI. 0.2101 gr. of the substance gave by the method of Carius 

 0.0813 gr, of argentic bromide. 

 VII. 0.2078 gr. of the substance gave 0.0792 gr. of argentic bromide. 

 VIII. 0.2054 gr. of the substance give 0.077G gr. of argentic bromide. 



Found. 

 I. II. III. IV. v. VI. VII VIII. 



Carbon 31.79 31.84 32.03 



Hydrogen 2.56 2.40 2.42 



Nitrogen 11. 60 11.20 



Bromine 16.47 16.22 16.08 



These analytical results agree best with the percentages required 

 by a substance formed from the bromtrinitrophenylmalonic ester by 

 replacing one of its atoms of hydrogen by the radical XO2, as is seen 

 from the following table. 



Carbon 

 Hydrogen 

 Nitrogen 

 Bromine 



Our reasons for the position assigned to the radical NO2 in this 

 formula, and for supposing that it is not a nitro group (— N = O2), 

 but a nitrite ( — O — N=:0), have been already stated in the intro- 

 duction to this paper. The yield is satisfactory on the whole ; 5 gr. 

 of bromtrinitrophenymalonic ester gave 3.26 gr. of the substance,* 

 mstead of the 5.5 gr. required by the calculation, that is, 59 per cent 

 of the theoretical yield. 



Properties of the Nitrite of Bromtrinitrophenylmalonic Ester. — It 

 occurs usually in short thick well developed glistening white prisms, 

 with terminations consisting of two planes at both ends, which seem to 

 indicate that the crystals belong to the raonoclinic system. Less com- 

 monly the prisms are long and rather slender, with terminations similar 

 to those of the shorter form. Its behavior when heated is very charac- 

 teristic. If a tube containing some of it is dipped into an oil bath at 

 124°-126°, the substance turns red round the sides, then deeper, and 

 the action gradually runs through the mass, until after a second or two 

 the whole is melted forming a dark blood-red liquid, which occupies 

 mauy times the volume of the original substance, and contains bubbles 



* In addition to this amount 7 gr. of bromtrinitroplienyltartronic ester 

 was obtained from the mother liquors. 



