156 PROCEEDINGS OF THE AMERICAN ACADEMY. 



seemed to have no action even when warmed with it for several min- 

 utes on the water bath. The constitution of this monobromphenylene 

 diamine is probably NH2. H. NHg. H. Br. H, as the tribromdinitro- 

 benzol made from symmetrical tribrombenzol loses all its bromine when 

 reduced under the conditions used in obtaining the monobromphenylene 

 diamine from tetrabromdinitrobenzol. 



Bromide of Monobromphenylene Diamine, C6H3Br(NH3Br)2. 



Monobromphenylene diamine was mixed with distilled hydrobroraic 

 acid (boiling point 124°-125°), and the liquid heated to boiling. The 

 solid was then brought into solution by the careful addition of just the 

 proper amount of water to the boiling solution, after which more of the 

 hydrobromic acid was added, until crystallization began, when the mix- 

 ture was allowed to cool ; the crystals thus obtained were washed 

 with hydrobromic acid and then with ether, dried by pressure with 

 filter paper, and washed with ether a second time. After drying over 

 sulphuric acid the salt was analyzed with the following result : — 

 0.2474 gram of the substance gave according to the method of Carius 

 0.3945 gram of argentic bromide. 



Calculated for 

 CeHsBrCNIIjBr),. Found. 



Bromine 68.77 G7.86 



This analysis leaves much to be desired, but the result is near enough 

 to show that the formula given above is correct. The salt forms 

 colorless transparent glassy crystals, which look like cubes under the 

 microscope ; freely soluble in water, slightly in hydrobromic acid. 



Teirahromphenylene Diamine, C6Br4(NH2)2. 



This substance was made by dissolving the monobromphenylene 

 diamine, melting at 93°-94'^ in ether and adding a slight excess of 

 bromine ; the product, after recrystallization from a mixture of chloro- 

 form and ligroine, showed the constant melting point 212^-213°, when 

 it was dried and analyzed with the following result: — 

 I. 0.2357 gram of the substance gave by the method of Carius 0.4166 



gram of argentic bromide. 

 11. 0.2493 gram of the substance gave 0.4432 gram of argentic bro- 

 mide. 



Bromine 



