JACKSON AND CALVERT. DERIVATIVES OP BENZOL. 131 



action even after standing three days. This was proved by testing the 

 aqueous washings for halogens with negative results, and recovering 

 essentially all of the tribromiodbenzol used. 



The following reagents had no effect on the tribromiodbenzol : 

 sodic phenylate in alcoholic solution boiling, sodic hydrate in aqueous 

 solution boiling, sodic carbonate in aqueous solution boiling, ziiicic 

 oxide and water in a sealed tube at 200° for twelve hours, argentic 

 acetate in aqueous solution boiling, aniline boiling, tin and hydro- 

 chloric acid, sodium malonic ester both cold and hot. The proof that 

 no action had taken place in these experiments was obtained either by 

 the recovery of the unaltered tribromiodbenzol, or by tests for a salt 

 of the halogens which gave negative results. In most cases both 

 methods of proof were applied. 



To determine whether the removal of the iodine was due to the 

 loosening effect of the three atoms of bromine or to the slight attrac- 

 tion of iodine alone for carbon, iodbenzol was treated with sodic 

 ethylate under the same conditions which had produced an action on 

 the tribromiodbenzol ; but after heating the mixture for an hour and 

 a half no test for sodic iodide could be obtained, showing that there 

 had been no action. 



Action of Fuming Nitric Acid on Trihromiodhenzol. 



When tribromiodbenzol was treated with fuming nitric acid, it lost 

 its white crystalline appearance even in the cold, and became con- 

 verted into a yellow powder. If the mixture was allowed to stand at 

 ordinary temperatures over night, and then water added to it, iodine 

 appeared both in scales and in the form of vapor, as a great amount of 

 heat was given off. The identity of the iodine was also established 

 by the smell and the violet color of its solution in carbonic disulphide. 

 If now the insoluble portion was washed with cold alcohol until free 

 from iodine, and then recrystallized several times from a mixture of 

 benzol and alcohol, it showed the constant melting point 191°, which 

 indicated that the substance was tribromdinitrobenzol, and this was 

 confirmed by the following analysis. 



0.3375 gram of the substance gave by the method of Carius 0.4740 

 gram of argentic bromide. 



Calculated for C6HBr3(N02)2. Found. 



Bromine 59.26 59.78 



