OF ARTS AND SCIENCES. 75 



Finally the following quantitative results were obtained : — 



Organic product from 20 grs. orthobrombenzylbromide 10.85 grs. 

 Calculated product if free from bromine 7.12 " 



Bromine not removed by the sodium 3.73 " 



Bromine in 20 grs. orthobrombenzylbroniiJe . . . 12.88 " 

 Bromine removed as bromide of sodium 9.71 " 



Bromine not removed by the sodium 3.17 " 



The " bromine removed as bromide of sodium " was determined 

 by precipitating 7.727 grs. of the wash-water with argentic nitrate, 

 which gave 1.482 grs. of argentic bromide. As the weight of the 

 wash-water was 119 grs., this corresponds to the result given above. 

 The two determinations of the amount of bromine not removed by 

 the sodium agree as closely as could be expected when the losses re- 

 sulting from the repeated extraction and washing of the viscous organic 

 products are taken into account. 



75.4 per cent of the whole amount of bromine contained in the 

 orthobrombenzylbromide was therefore removed by the sodium. 



Determination of the Amount of Anthracene hy Luck's* Method. — 

 1.04 grs. of the product, oxidized, first with chromic anhydride dis- 

 solved in glacial acetic acid, and afterward with an alkaline solution 

 of potassic permanganate, gave 0.158 gr. of anthrachinone, corre- 

 sponding to 0.135 gr. of anthracene, that is, 1.409 grs. from the 20 grs. 

 of orthobrombenzylbromide used, or 19.78 per cent of the theoretical 

 yield. 



Determination of the Amount of Phenanthrene. — 2.44 grs. of the 

 original product, oxidized carefully by adding a strong aqueous solu- 

 tion of chromic anhydride to a hot solution of the substance in glacial 

 acetic acid as long as a drop of the oxidizing agent made the liquid 

 boil,t on extraction of the product with acid sodic sulphite and acidifi- 

 cation with nitric acid, yielded 0.05 gr. of phenanthrenechinone, which 

 corresponds to 0.0428 gr. of phenanthrene ; that is, from 20 grs. of 

 orthobrombenzylbromide 0.190 gr., or 2.66 per cent of the theory. 

 The amount of phenanthrene actually formed must have been some- 

 what larger than this, as some of the chinone was undoubtedly de- 

 stroyed by the chromic anhydride, — in fact, the operation can hardly 

 be called a quantitative one. 



* Zeitschr Anal. Cliem., 73, p. 347; '74, p. 251. 



t Lieberniann and Hiirmann, Ber. d. ch. G., '79, p. 691. 



