OP ARTS AND SCIENCES. 171 



At the end of the ten minutes the solution was poured into an evapo- 

 rating dish and allowed to evaporate to dryness spontaneously, washed 

 with water to remove sodic bromide, and the reddi>h brown substance 

 insoluble in water purified by crystallization from alcohol with the aid 

 of boneblack until it showed the constant melting point 133°, when it 

 was dried at 100°, and analyzed with the results given under I. and 

 III. More than a year ago G. D. Moore with one of us obtained 

 under somewhat different conditions the same substance as shown by 

 the melting point and crystalline form, and we therefore add the 

 analyses made of it by Dr. Moore at that time, II., IV., and V. 



I. 0.2200 gr. of the substance gave on combustion 0.3752 gr. of 



carbonic dioxide and 0.0950 gr. of water. 

 II. 0.2320 gr. of the substance gave 0.3990 gr. of carbonic dioxide 

 and 0.0995 gr. of water. 



III. 0.2112 gr. of the substance gave 21 c.c. of nitrogen at a tem- 



perature of 2G'' and a pressure of 754.8 mm. 



IV. 0.2299 gr. of the substance gave 22.3 c.c. of nitrogen at a tem- 



perature of 23° and a pressure of 762.2 mm. 

 V. 0.2142 gr. of the substance gave 20.3 c.c. of nitrogen at a tem- 

 perature of 2 2°. 5 and a pressure of 767 mm. 



IV. 



10.96 10.81 



It contained no bromine. 



These analyses prove that the substance is the dinitroresorcine 

 diethylether which must have been formed from the tribromdinitro- 

 benzol C,;HBr3(NOo)2 by the replacement of two of its atoms of bro- 

 mine by two ethoxy radicals (C2II5O), the third by hydrogen, and we 

 have here another case of the curious replacement of bromine by 

 hydrogen in preference to its replacement by a radical combined with 

 sodium, which was first observed in the study of the action of sodium 

 malonic ester upon tribromdinitrobenaol, and which induced us to 

 undertake the present investigation. Since this dinitroresorcine 

 diethylether melts at 133°, it is isomeric with the one * already known 

 melting at 75°. 



* Aronheim, Ber. d. ch. G., xii. 32. 



