320 Drs. Muspratt and Hofmann on Nitr aniline, 



as at least to solve the questions that remained unanswered 

 in Zinin's experiments. By doing so we very soon obtained 

 results which had escaped the observation of Zinin, and which 

 brought us to the point we aimed at. 



For our research we had to prepare a large quantity of di- 

 nitrobenzole. The transformation of nitrobenzole into dinitro- 

 benzole proceeds very slowly, even when it is boiled repeatedly 

 with the strongest nitric acid. It is obtained however very 

 speedily by dropping benzole or nitrobenzole into a mixture 

 composed of equal parts of fuming nitric acid and concen- 

 trated sulphuric acid, as long as the liquid remains homoge- 

 neous. The liquid is now boiled for a few minutes and then 

 allowed to cool. A thick mass of dinitrobenzole is formed, 

 which by washing with water is freed from all adhering acid. 

 One recrystallization from alcohol furnishes this body in long, 

 shining, needle-shaped prisms of absolute purity. 



A combustion of these crystals gave us the following re- 

 sults : — 



0*2978 grm. dinitrobenzole gave 0*4728 grm. carbonic acid 

 and 0*0650 grm. water. 



These results afford in 100 parts — 



Preparation of Nitraniline. 



When an alcoholic solution of dinitrobenzole is saturated 

 with ammoniacal gas it assumes a dark red colour, and by 

 then passing a stream of hydrosulphuric acid gas through 

 this solution, a large quantity of crystals of sulphur are de- 

 posited. By continuing to pass hydrosulphuric acid gas 

 through the solution until only a small quantity of sulphur 

 precipitates, it will contain very little undecomposed dinitro- 

 benzole. By adding hydrochloric acid to this solution and 

 boiling, a new portion of sulphur, mixed with a trace of dini- 

 trobenzole, is thrown down. The whole is now filtered, and 

 to the filtrate potassa is added, a brown matter separates, 

 which unites and settles in a resinous mass at the bottom of 

 the vessel. We washed this matter with cold water until all 

 the alkali was removed. It dissolved completely in alcohol 



