OS PROCEEDINGS OF THE AMERICAN ACADEMY. 



(1.) CupRiANiLiNE Bromide, Cu(C6H7N)2Br2. 



This compound is formed as a brown powder whenever cupric bro- 

 mide is added to an alcoholic solution of aniline ; but a much moi'e 

 beautiful crystalline preparation is obtained when the solution contains 

 acetic acid. For example, three grams of cupric bromide were dis- 

 solved in about forty cubic centimeters of alcoliol ; and to this were 

 added twenty cubic centimeters of acetic acid and fifteen cubic centi- 

 meters of aniline. The mixture turned green immediately, and beau- 

 tifully brilliant brown crystalline flakes of cuprianiline bromide were 

 deposited. Nothing could be easier than the preparation of this sub- 

 stance. 



From analogy to the cupriammonium compounds, one would have 

 expected the cuprianiline aceto-bromide to have been formed under 

 conditions given above ; but this is not the case unless the solution 

 contains a large per cent of cupric acetate. 



Among a great number of samples of cuprianiline bromide, which 

 have all given satisfactory analytical results, at least four colors have 

 been observed. A few preparations consisted of long glossy black 

 crystals, others consisted of dark brown shining flakes. Yet others 

 were of a lighter brown, and some were almost of a golden yellow. 

 Possibly the difference was due to variations in the thickness of the 

 individual crystals. 



The new compound is insoluble in alcohol and glacial acetic acid. 

 When mixed with water it is decomposed at once into a basic bromide 

 of copper, aniline hydrobroraide, and a little free aniline. Alkalies 

 and acids of course decompose it. 



In order to prepare the substance for the electrolytic determination 

 of the copper it was treated with nitric acid, evaporated to dryness, 

 and ignited. The residue was dissolved in a mixture of nitric and sul- 

 phuric acids ; the former acid was expelled on the steam bath, and the 

 copper was separated in the usual fiishion. Bromine was determined 

 as argentic bromide ; and the aniline was calculated from the amount 

 of carbon dioxide yielded by the combustion of the compound. As a 

 final check upon the results, the nitrogen present was determined 

 according to the method of Dumas. 



Analyses of Cu(C6H7N)2Br2. 



I. 0.1978 gram of the substance yielded 0.0.'>08 gram of copper. 

 II. 0.2299 gram of the substance yielded 0.0357 gram of copper. 



