OP ARTS AND SCIENCES. 217 



orthobromtoluol, and 24 grammes of this gave on the first fractioning 

 19 grammes of a colorless liquid boiling between 179^ and 182° ; that is, 

 about thirty-six per cent of the theoretical yield, whereas the diazoper- 

 bromide furnishes under the best conditions only ten per cent. The 

 new method has the further advantages of taking much less than half 

 the time occupied by either of the old ones, and the product is not 

 contaminated with the nitro compounds which compelled Hiibner and 

 Majert to reduce before rectifying. Von Richter * has also obtained 

 tetrabrombenzole by the action of nitrous anhydride on a mixture of 

 tribromaniline with hydrobromic and glacial acetic acids ; he ascribes 

 the reaction to the presence of the negative atoms, and announces his 

 intention of trying similar experiments with compounds containing 

 fewer bromine atoms or nitro groups ; that the reaction is not due to 

 the presence of such negative radicals is proved by the previous 

 researches of Hiibner and Majert, which he seems to have overlooked, 

 and the results given above. I should not have intruded on Von 

 Richter's field of work, had it not been necessary for me to obtain the 

 orthobromtoluol, but I felt the less hesitation in doing so, as I am 

 unable to see that his method differs in any essential particular from 

 that of Hiibner and Majert, published nearly two years before the 

 appearance of his article. 



The orthobromtoluol was converted into orthobrombenzylbromide 

 by treatment with bromine in the way described under the para com- 

 pound. The purification of the substance was a matter of some diffi- 

 culty, as it seemed to be completely decomposed by rectification, and 

 converted into the alcohol by distillation with steam ; the method 

 finally adopted was distillation in a stream of the vapor from aqueous 

 hydrobromic acid, as described under the metabrombenzylbromide ; the 

 first fifth of the distillate was rejected to make sure of the absence of 

 orthobromtoluol ; that which came over later was washed till it ceased 

 to give an acid reaction, and then dried in vacuo. In this way, 17 

 grains of pure orthobrombenzylbromide were obtained from 18 grains 

 of orthobromtoluol. 



Its purity was established by the following bromine determina- 

 tion : — 



0.5035 gr. of substance gave after ignition with CaO 0.7608 gr. of 



AgBr. 



Required for C-HgBro. Found. 



Bromine 64.0 64.30 



* Von Richter, Ber. D. Ch. G., 1875, p. 1428. 



