OF ARTS AND SCIENCES. 1G7 



time to run to an end, the mixture was allowed to stand in a corked 

 flask at ordinary temperatures for two or three days, and then was 

 filtered to remove a considerable amount of solid matter which had 

 separated, and the filtrate allowed to evaporate spontaneously. The 

 solid remaining on the filter was washed with water to remove sodic 

 bromide, the presence of which was proved by testing this wash water 

 with argentic nitrate after acidification with nitric acid, and the por- 

 tion insoluble in water added to the main product when that had been 

 brought to the same degree of purity. This main product was de- 

 posited from the filtrate by the spontaneous evaporation of the sol- 

 vent, and after washing with water was purified by crystallization 

 from hot alcohol until it showed the constant melting point 184°. 

 It is worth mentionmg that the earlier crystallizations yielded round 

 woolly masses of fine needles, which were uradually converted, as the 

 substance approached purity, into well formed prisms or plates, since 

 this change in the crystalline habit furnishes a convenient indication 

 of the comparative purity of the substance. The analyses of the sub- 

 stance dried at 100° gave the following results: — 

 I. 0.2616 gr. of the substance gave on combustion 0.3426 gr. of 



carbonic dioxide and 0.0904 gr. of water. 

 II. 0.2753 gr. of the substance gave 21.9 c.c. of nitrogen at a tem- 

 perature of 25° and a pressure of 745.5 mm. 

 III. 0.1830 gr. of the substance gave according to the method of 

 Carius 0.1032 gr. of argentic bromide. 



Calculated for Found. 



C6HBr(C2nr,0)a(N02)2. I. U. IH. 



Carbon 35.83 35.72 



Hydrogen 3.28 3.84 



Nitrogen 8.36 8.70 



Bromine 23.89 24.00 



There can be no doubt, therefore, that this substance melting at 

 184° is the bromdinitroresorcine diethylether formed by the replace- 

 ment of two atoms of bromine by two of the ethoxy radicals. 



The yield of bromdinitroresorcine diethylether is far from good, 

 20 gr. of tribromdinitrobenzol giving in no instance more than 4.6 gr 

 of this substance instead of the 16.5 gr. required if the whole of the 

 tribromdinitrobenzol had been converted into it, that is, about 28 per 

 cent ; and, in fact, the alcoholic mother liquors from its purification 

 yielded on evaporation a viscous residue in large quantity, our un- 

 satisfactory work upon which will be described after the statement 

 of the properties of the bromdinitroresorcine diethylether. We may 



