BENZENE. 257 



pounds. Is scarcely acted upon by alkalies ; with acids, 

 however, it decomposes easily, yielding formic acid and 

 anilin. 



Nitrosubstitution-products, Nitrobenzene, C 6 H 5 

 (NO 2 ), is formed, when benzene is added gradu 

 ally to very concentrated nitric acid, which is kept 

 cool. Bright yellow liquid, with an odor similar to 

 that of oil of bitter almonds. Boils at 205, and con 

 geals at &.Paradimtrobenzene, C 6 H 4 (E&quot;0 2 ) 2 , is pro 

 duced by heating the preceding compound for a long 

 time with very concentrated nitric acid ; more readily 

 by dropping benzene into a mixture of two volumes 

 concentrated sulphuric acid, and one volume very con 

 centrated nitric acid. Crystallizes from alcohol in very 

 long, shiny, nearly colorless needles, that fuse at 86. 



By the action of nitric acid or nitric-sulphuric acid 

 on chlorine, bromine, and iodine substitution-products 

 of benzene, mono- and dinitro-derivatives of these com 

 pounds are formed. Usually several isomeric modifi 

 cations are produced at the same time, the constitution 

 of which is as yet unknown. Nearly all of these 

 compounds are solid and crystallize well. All these 

 modifications of nitrochlorbenzene C 6 H 4 (N0 2 )C1 are 

 known ; two of them are solid and have the fusing 

 points 85 and 46; the third is fluid, and boils at 240; 

 also of nitrobrombenzene C 6 II 4 (N0 2 )Br, all three modifi 

 cations are known ; they all crystallize in yellowish 

 prisms, and have the fusing points, 125, 50, and 

 31.ffltroiodobenzene C 6 H 4 (N0 2 )L Of this, two modi 

 fications are known (fusing points, 171. 5 and 34) ; 

 also of nitrobenzonitrile C 6 II 4 (N0 2 )CN, (metanitroben- 

 zonitrile, from benzonitrile with nitric acid and from 

 metanitrobenzamide with phosphorus pentachloride. 

 Fusing point, 117-118. Paranitrobenzonitrile from 

 paranitrobenzamide with phosphoric anhydride : lami- 

 nse ; fusing point, 139). 



Dinitrochlorbenzene, C 6 1P(N0 2 ) 2 C1, from chlor- 

 benzene with nitric-sulphuric acid ; and from dinitro- 



22* 



