256 BENZENE. 



from benzene. It fuses at 98. Pentabrombenzene 

 C 6 HBr 5 needles sublime without decomposing;, fuse 

 above 240. 



Iodine substitution-products. These are pro- 

 duced by heating benzene with iodine and iodic acid 

 at 200-240 ; by the action of iodine and phosphorus 

 on phenol ; and by treating silver benzoate with iodine 

 chloride. Monoiodobenzene C 6 H 5 I, colorless liquid, boil- 

 ing at 185. .Diiodobenzene C 6 H 4 I 2 , laminae, fusing 

 point, 127 ; boiling point, 21 f J. Triiodobenzene 

 C 6 H 3 I 3 , needles, fusing at 76, sublimable without 

 decomposition. 



Fluorbenzene, C 6 H 5 F1. By heating a mixture of 

 calcium fluorbenzoate and calcium hydroxide. Crys- 

 talline mass. Fusing point, 40 ; boiling point, ISO- 

 loo . 



Cyanbenzene (Benzonitrile), C 6 H 5 .CJSr, is formed by 

 the distillation of a mixture of potassium sulphoben- 

 zolate with potassium cyanide ; by the distillation of 

 ammonium benzoate or hippuric acid ; by heating ben- 

 zamide with benzoyl chloride or benzoic anhydride ; 

 and in small quantities in a great many other ways. 

 Colorless oil, boiling at 191. Combines directly with 

 hydrogen, bromine, hydrobromic and hydriodic acids ; 

 and yields benzoic acid and ammonia when heated 

 with alkalies. 



Paradieyanbenzene, C 6 H 4 (CN) 2 . By distilling a 

 mixture of potassium parabromsulphobenzolate or 

 paradisulphobenzolate with potassium cyanide. Color- 

 less prisms, sublimable without decomposition. Heated 

 with alkalies, it yields terephtalic acid. 



A compound isomeric with benzonitrile is 



Phenylcarbylamine (Phenyl cyanide), C 6 IF.CN. 

 Is produced by distilling a mixture of anilin, chloro- 

 form, and alcoholic potassa. Liquid, not distillable 

 without decomposition. Combines with other cyanides, 

 especially silver cyanide, forming crystallizing com- 



