M. Couper on Bromobenzole and Dibromobenzole. 455 



spending homologucs of olefiant gas, inasmuch as these hydro- 

 carbons exert a I'educing action on the acid at the temperature 

 necessary for the reaction. Berthelot has, however, lately* 

 found that certain homologues of olefiant gas combine with the 

 hydrogen acids, and that in this way the corresponding alcohols 

 may be prepared. 



Propylene gas, C^ H^, heated with concentrated hydrochloric 

 acid for several days to 100° C, is completely absorbed with the 

 formation of chloride of propyle, — 



C^HS + HCl = C^H^Cl. 



Propylene. Chloride of 



propyle. 



By treating this chloride of propyle with solution of potash, 

 propylic alcohol, C^ H** 0^, is obtained. In like manner amy- 

 lene, C'° H''', unites, though more slowly and less completely, 

 with hydrochloric and hydrobromic acids to form chloride and 

 bromide of amyle, from which amylic alcohol is obtained. 



Caprylene, C"'H'^, and sethalene, C^^H^^, also combine with 

 these acids, although the action, especially of the latter sub- 

 stance, is still slower and less complete. 



Couperf describes two bromine substitution-products of ben- 

 zole, obtained by bringing bromine vapour into contact with 

 boiling benzole. 



Bi-omoben~ole (bromide of phenyle), C'^ H^ Br., boils atl50° C. 

 It is a colourless liquid, with an odour resembling benzole. It 

 does not solidify at —20° C. Heated with fuming nitric acid, 

 there is formed a crystalline nitro-substitutiou product of the 

 formula C'^ H"* (NO'') Br, which melts at 90° C, but cannot be 

 distilled without decomposition. 



Bromobenzole dissolves in fuming sulphuric acid ; the solu- 

 tion, on standing, deposits crystals of sulphobromobenzolic acid. 

 This acid is very deliquescent ; it forms with ammonia an almost 

 insoluble crystallizable ammonia salt of the composition 

 C'2H^Br2S03NH3. 



By the continued action of excess of bromine on bromoben- 

 zole, hydrobromic acid is evolved, and dibromobenzole, C'^H'^Br^, 

 is formed in crystals, which are purified by recrystallization from 

 aether. It forms beautiful oblique rhombic prisms, which melt 

 at 89° C, and distil without decomposition at 219° C. 



Buff and Wohlcr, in continuing their researches on siliciuretted 

 hydrogen %, with a view of finding a method for the preparation 



* Comptes Rendus, vol. xliv. p. 1350. 



t Ibifl. vol. xlv. p. 230. Liebig's Annakn, November 1857. 



t I'hil. iMag. August 1«57. 



