178 ANILINE 



For this purpose, tho following proportions havo been found convenient by the 

 writer ; mix in a retort Ib. of iron filings, with about 2 ounces of acetic acid, then 

 add about an equal volume of nitrobenzol. After a few minutes a brisk effervescence 

 sets in, and the aniline distils over together with water. The reaction may require 

 to be aided by the application of a very gentle heat ; but it takes place with the 

 greatest ease, and an ordinary condensing arrangement should bo employed. The 

 aniline having BO nearly the density of water, does not readily separate on the 

 surface, but the addition of a small quantity of salt, which dissolves in the water, 

 brings it to the surface. It may then be decanted off, dried by standing for a 

 short time over chloride of calcium, and then purified by rectification, as before 

 described. 



Properties. Aniline is one of tho organic basic derivatives of ammonia. In fact, 

 it may be viewed as ammonia in which one equivalent of hydrogen is replaced by 

 the compound radical Phenyl (C 8 H 4 ), thus : 



H 



Just as phenyl is one of a series of homologous radicals, so aniline ie the first of 

 a series of homologous bases, in which the one equivalent of hydrogen is replaced by 

 these radicals respectively, thus : 



Homologous Radicals. Homologous Bases. 



Phenyl . . . C 8 H s - Aniline . . . " TO' 



Toluyl . . . C 7 H 7 - Toluidine >T ' ' 



Xylyl . . . . C 8 H 9 - Xylidine . 



cry TTH 

 Chunyl . . . C 9 H 11 - Cumidine . . . XT ' 



Cymyl . . . C 10 H 18 - Cymidine . 



When pure, it is a colourless liquid of a high refractive power, density 1-028, and 

 of an aromatic odour. It is slightly soluble in water, and mixes in all proportions 

 with alcohol and ether. It boils at 360 F. (182 C.). It dissolves sulphur and 

 phosphorus when cold and coagulates albumen. It has no action on litmus-paper, 

 but turns delicate vegetable colours, such as dahlia-petal infusion, blue. 



Its basic characters are well developed ; thus it precipitates the oxides from the 

 salts of iron, zinc, and alumina, just like ammonia, and yields, with chloride of 

 platinum, a double salt similar to ammonia, the chloro-platinate of aniline (2C 8 H 8 

 NCI, PtCl'), which on ignition is entirely decomposed, leaving only a residue of 

 platinum. These characters, together with tho beautiful blue colour which it strikes 

 with solution of bleaching-powder, or the alkaline hypochlorites generally, are suffi- 

 cient for the recognition and distinction of this body. (See PHENYL, &c. &c.) 



SALTS OF ANILINE. Aniline combines with acids, forming a long series of salts 

 which are in every respect analogous to the corresponding salts of ammonia. They 

 are nearly all soluble and crystallisable, and are decomposed by the mineral alkalies 

 with liberation of aniline. They are generally colourless, but become red by expo- 

 sure to the air. 



Sulphate of Aniline. (C 6 H 7 N ; H? SO 4 .) This salt is employed in the manu- 

 facture of Mr. Perkins' aniline colours. It is prepared by treating aniline with 

 dilute sulphuric acid, and evaporating gently till tho salt separates. It crystallises 

 from boiling alcohol in the form of beautiful colourless plates of a silvery lustre, for 

 the salt is scarcely at all soluble in cold alcohol. It is very soluble in water, but 

 insoluble in ether. 



The crystals redden by exposure to the air ; they can be heated to the boiling point 

 of water without change, but when ignited they are charred with disengagement of 

 aniline and sulphurous acid. 



Oxalate of Aniline. (2C 8 H 7 N ; C 2 H* O 4 .) This is one of the best defined 

 Baits of aniline : it separates as a crystalline mass on treating an alcoholic solution of 

 oxalic acid with aniline. It is very soluble in hot water, much less so in cold, only 

 slightly soluble in alcohol, and insoluble in ether. 



A large number of other salts are known : tho hydrochlorate, hydrobromate, 

 hydriodate, nitrate, several phosphates, citrate, tartrate, &c. &c. ; but they arc of 

 purely scientific interest. The same remark applies to the various products of tho 



