OP ARTS AND SCIENCES. 173 



mixture heated to gentle boiling for about ten minutes in a flask 

 under a return condenser, when it had taken on a dark red color, and 

 the curious odor observed in making the dinitroresorcine diethylether 

 was very perceptible. The solvent was then allowed to evaporate 

 spontaneously, and the residue washed with water, which removed 

 sodic bromide (as was proved by the addition of argentic nitrate) and a 

 red impurity. It was then purified by crystallization from hot alco- 

 hol, until it showed a constant melting point, when we found that this 

 treatment had lowered the melting point from 184°, that of the brom- 

 dinitroresorcine diethylether, to 133°, that of the dinitroresorcine 

 diethylether, which substance the product also resembled in appear- 

 ance and solubility. To remove all doubt about its nature it was 

 dried at 100° and analyzed, with the following results : — 



0.1378 gr. of the substance gave on combustion 0.2354 gr. of carbonic 

 dioxide and 0.0616 gr. of water. 



Calculated for 

 CoH2(C2n50)o(N02)2. Found. 



Carbon 46.88 46.58 



Hydrogen 4.69 4.97 



This proves that the substance is the dinitroresorcine diethylether, 

 and that the principal action of the hot sodic ethylate upon the brom- 

 dinitroresorcine diethylether was the replacement of its bromine by 

 hydrogen. 



After the experiment just described had proved that the bromine 

 in bromdinitroresorciue diethylether could be replaced by hydrogen 

 by means of boiling sodic ethylate, it seemed of interest to determine 

 whether the same change could be brought about by other reagents, 

 and we tried first alcohol alone, which might produce this action by 

 giving aldehyd and hydroliromic acid as secondary products, although 

 this was not at all probable since the bromdinitroresorcine diethyl- 

 ether was purified by crystallization from hot alcohol ; and indeed, 

 after boiling it with alcohol for a long time in a flask under a return 

 condenser, the result was entirely negative, nothing but unaltered 

 bromdinitroresorcine diethylether melting at 184° being obtained on 

 evaporation of the alcoholic solution. 



From the action of malonic ester on bromdinitroresorcine diethyl- 

 ether we expected better results, because, although it is true that 

 malonic ester has no action on tribromdinitrobenzol (see these Pro- 

 ceedings, xxiv. 308, and the concluding section of this paper), in the 

 formation of bromdinitrophenylmalonic ester it seems to replace one 



