140 PROCEEDINGS OF THE AMERICAN ACADEMY. 



stituted for three of hydrogen in its molecule, and the tetrabrom- 

 phenyleue diamine is formed, which melts at 212°-213°. 



The presence of the bromine in the molecule of metaphenylene dia- 

 mine has a strong effect on its tendency to form salts and on the composi- 

 tion of the salts formed. The tetrabrom and tribrom compounds do not 

 form salts under ordinary conditions, but tribromphenylene diamine can 

 be converted into its chloride by passing hydrochloric acid through a 

 solution of it in benzol ; this salt, however, gives up part of its hydro- 

 chloric acid at ordinary temperatures, the whole of it at 100°. The 

 dibroraphenylene diamine, on the other hand, forms salts more easily, 

 and its chloride is only partially decomposed at 100°, while the bromide 

 of this base seems to be even more stable. All three of these salts con- 

 tain but one molecule of the acid, the ciiloride of dibromphenylene dia- 

 mine, for example, having the following formula CgHaBraNHsClNHo. 

 The monobromphenylene diamine forms salts still more easily, and 

 they are also more stable. The bromide contains two molecules of 

 hydrobromic acid having the formula C6H3Br(NH,..Br)2. We have 

 also prepared the tribromphenylene diacetamide, which does not melt 

 at 330°, and the tribromphenylene diurethane melting at 212.° 



Experimental Part. 

 Tribrommetaphenylene Diamine C6lIBr3(NH2)2. 



The most convenient method for preparing this substance consists in 

 passing a stream of air and bromine vapor into a solution containing meta- 

 phenylene diamine, for instance that obtained by adding sodic hydrate 

 or carbonate to the product of the reduction of metadinitrobeuzol with 

 tin and hydrochloric acid until all the tin is precipitated and filtering 

 out the hydrate of tin. In adding the bromine an excess must be 

 avoided, as this turns the product black, and we have therefore found 

 it well to filter the precipitate out by means of cheese-cloth as fast as a 

 sufficient quantity of it was formed, continuing the action of the bro- 

 mine vapor on the successive filtrates as long as a precipitate appeared. 

 The crude product, which was always dark colored, was dried, and then 

 crystallized from alcohol containing a little benzol until it showed the 

 constant melting point 158°, when it was dried at 100° and analyzed 

 with the following results : — 

 I. 0.1459 gram of the substance gave by the method of Carius 



0.2392 gram of argentic bromide. 

 11. 0.2022 gram of the substance gave 14.65c.c. of nitrogen at a 



temperature of 19° and a pressure of 771.9 mm. 



