JACKSON AND CALVERT. — DERIVATIVES OF BENZOL. 129 



to judge fi'om his statement, we give it in detail. Ten grams of sym- 

 metrical tribromaniline were mixed with moderately dilute sulphuric 

 acid in such proportion that there was one molecule of the acid to each 

 molecule of the tribromaniline ; the calculated amount of solid sodic 

 nitrite was then added in small quantities at a time, shaking the 

 loosely corked flask after each addition until the red fumes were 

 absorbed. The mixture after standing over night was filtered, and 

 then treated with hydriodic acid till there was no further action. The 

 slightly brown precipitate was washed with water, and purified by 

 crystallization from a mixture of benzol and alcohol, when it showed a 

 melting point of 104°. Silberstein gives 103°. 5. For greater safety 

 it was analyzed, with the following result. 



0.3374 gram of the substance gave 0.6119 gram of a mixture of argen- 

 tic bromide and iodide. 



Calculated for Cell^BrjI. Found. 



Iodine and Bromine 83.24 83.32 



We find the solubilities of the substance the same as those given by 

 Silberstein, but we do not agree with him when he says it sublimes 

 easily, as we have found that it sublimes much less easily than sym- 

 metrical tribrombenzol. 



To study the action of sodic ethylate on tribromiodbenzol, 6 grams 

 of it were dissolved in anhydrous benzol, and mixed with 40 c.c. of an 

 alcoholic solution of sodic ethylate, containing 2 grams of sodium, 

 that is, more than enough to remove all the halogen atoms present. 

 The mixture was then heated on the steam bath under a return con- 

 denser for one hour, when the liquid had taken on a dark color, and a 

 brownish precipitate had appeared ; the liquid was now evaporated, 

 and the residue treated for half an hour with a large quantity of water, 

 filtered, and washed, when it weighed 4.1 grams. Upon subliming 

 this residue, 2 grams of sublimate were obtained in small white needles 

 which melted at 119°-120°, the melting poiut of symmetrical tribrom- 

 benzol. An analysis of the sublimate gave the following result. 



0.2612 gram of the substance gave by the method of Carius 0.4695 

 gram of argentic bromide. 



Calculated for CgllsBrs. Found. 



Bromine 76.18 76.51 



There can be no doubt, therefore, that the substance is tribromben- 

 zol, formed by the replacement of the atom of iodine in the tribrom- 

 VOL. XXXI. (n. s. xxtii.) 9 



