OF ARTS AND SCIENCES. 291 



tion out of alcohol from the unaltered second product, which was then 

 purified by crystallization from boiling alcohol, or better chloroform, 

 until it showed the constant melting point 248°, when, after drying at 

 100°, it was analyzed with the following results : — 



I. 0.1711 gr. of the substance gave on combustion 0.0855 gr. of 

 carbonic dioxide and 0.0151 gr. of water. 

 II. 0.2100 gr. of the substance* gave 0.1075 gr. of carbonic dioxide 

 and 0.0103 gr. of water. 



III. 0.1846 gr. of the substance gave 3.5 c.c. of nitrogen at a tempera- 



ture of 17° and a pressure of 773 mm. 



IV. 0.1881 gr. of the substance gave, according to the method of 



Carius, 0.3418 gr. of argentic bromide. 



IV. 



77.34 



There can be no doubt, therefore, that this is the as yet undescribed 

 pentabromnitrobenzol. 



Properties. — The pentabromnitrobenzol crystallizes in very slender 

 little white needles, which melt at 248°. The substance is essentially 

 insoluble in water or ligroine ; nearly insoluble in cold ethyl or 

 methyl alcohol, more soluble when hot, but still sparingly ; the solu- 

 bility in glacial acetic acid or acetone is similar, except that it is much 

 more soluble in either of these solvents when hot than it is in alcohol ; 

 readily soluble in hot benzol or chloroform ; very soluble in ether or 

 carbonic disulphide. 



Although pentabromnitrobenzol was the usual impurity, on one 

 occasion a different product was obtained, which consisted of small 

 needles melting, after crystallization from benzol, at about 312°, essen- 

 tially insoluble in alcohol or soclic hydrate, and containing no nitrogen. 

 We inferred therefore that this was the hexabrombenzol, which is said 

 to melt above 315°, and to be almost insoluble in boiling alcohol, and 

 this inference was proved to be correct by the following analysis : — 



0.1303 gr. of the substance gave, by the method of Carius, 0.2666 

 gr. of argentic bromide. 



Calculated for C 6 Br 9 . . Found. 



Bromine 86.96 87.10 



