236 PROCEEDINGS OF THE AMERICAN ACADEMY. 



phate decomposed by the addition of a strong solution of sodic hydrate, 

 which set free the base as a pasty mass solidifying on cooling. This 

 base, after purification by crystallization from alcohol, showed the con- 

 stant melting point 50°, which is that of the diparabrombenzylamine* 

 (C6H4BrCH2)2NH. For greater security the chlorplatinate was pre- 

 pared and analyzed. Chlorplatinic acid added to an alcoholic solution of 

 the base gave a yellow precipitate, which was purified by washing with 

 alcohol, and dried in vacuo. 



0.1783 gram of the salt gave on ignition 0.0309 gram of platinum. 



Calculated for [(C7H,;Br),NH2]2PtCl|i, Found. 



Platinum 17.58 17.34 



The sulphuric acid filtrate from the crystals of the diparabrombenzyl- 

 amine sulphate was treated at first with sodic carbonate, and finally with 

 a large excess of sodic hydrate, and distilled with steam, the distillate 

 being collected in a series of flasks containing hydrochloric acid. After 

 the distillation was finished, the contents of the flasks were evaporated to 

 dryness on the steam bath, and the white residue dissolved in a little water 

 and converted into the chlorplatinate ; this was a yellow precipitate 

 crystallizing in octaiiedia, which was washed with water and alcohol, 

 dried in vacuo, and analyzed with the following results: — 



0.2061 gram of the chlorplatinate gave on ignition 0.0903 gram of 

 platinum. 



Calculated for (NH4)2PtCl8. Found. 



Platinum 43.91 ' 43.81 



It is evident from the experiment described above that the products of 

 the decomposition of diparabrombenzylcyanamide, when boiled with di- 

 lute sulphuric acid, are carbonic dioxide, diparabrombenzylamine, and 

 ammonia. The reaction, therefore, I'uns as follows: — 



(C6H4BrCHo)2NCN -f 2H.,0 = (CJl4BrCH,)oNH -f NHg + COj. 



* Jackson, These Proceedings, XVI. 254. 



