80 PROCEEDINGS OF THE AMERICAN ACADEMY. 



hot water, was purified by crystallization from a mixture of ligroin and 

 benzol, when it was found to melt at 133°, the melting point of the 

 dinitroresorcine diethylether discovered by Warren and one of us,* 

 which it also resembled in crystalline form. As Koch and one of us f 

 have 2^roved that this dinitroresorcine diethylether has the constitution 

 (00113)2 1. 3. (N02)2 4. 6, it follows that the dibromdinitrobenzol melt- 

 ing at 117° has the constitution Br^ 1. 3. (N02)2 4. 6, — a result which 

 confirms that already obtained from the action of aniline. 



Action of Sodic Phenylate with Symmetrical Dibromdinitro- 

 benzol. 



The sodic phenylate for this experiment was prepared by adding five 

 grams of powdered sodic hydi'ate to enough melted phenol to make a 

 pasty mass. While this was still in the viscous state, five grams of the 

 dibromdinitrobenzol were added little by little with constant stirring, the 

 beaker containing the mixture being kept cool with ice water. The 

 product, a dark brown solid mass, was treated with water, filtered, and 

 the insoluble portion recrystallized either from slightly dilute alcohol, or 

 from a mixture of benzol with a large excess of ligroin, until it showed 

 tlie constant melting point 129°, when it was dried in vacuo, and ana- 

 lyzed, with the following results : — 



I. 0.2494 gram of the substance gave on combustion 0.5563 gram of 



carbonic dioxide and 0.0903 gram of water. 

 II. 0.3746 gram gave on combustion 0.8457 gram of carbonic dioxide. 

 The water was unfortunately lost. 



Found. 



II. 



61.59 



The method of making sodic phenylate given above was adopted 

 because in alcoholic solution the sodic phenylate gave principally the 

 dinitroresorcine diethylether, and in aqueous solution there was no action 

 until high temperatures were reached, and then the yield was unsatis- 

 factory. 



* These Proceedings, XXV. 170. 

 t Ibid., XXXIV. 134. 



