130 BASIC BODIES. 



green ; when exposed to the air it becomes yellow, and is converted 

 into a resinous mass ; a solution of hypochlorite of lime, on the 

 addition of a few drops, assumes a violet colour ; with nitric acid, on 

 the other hand, aniline yields an indigo colour, and, by prolonged 

 action, is converted into picric acid ; with dilute chromic acid it 

 yields a black or greenish blue precipitate, 



Composition. According to the above formula aniline con- 

 tains : 



Carbon 12 atoms .... 77*419 



Hydrogen 7 .... 7'527 



Nitrogen 1 .... 15'054 



100-000 



Its atomic weight =11 62*5. According to Berzelius, aniline 

 consists of ammonia conjugated with a carbo-hydrogen=C 12 H 4 . 



Combinations. Aniline forms very characteristic, and, for the 

 most part, crystallisable salts, both with the oxygen and the hydro- 

 gen acids ; in the former, but not in the latter case, the salts assi- 

 milating an atom of water. 



The analogy between aniline and ammonia is further shown by 

 the circumstance that it, like the latter, under certain conditions, 

 may lose a portion of its hydrogen, and be converted with an acid 

 deprived of a portion of its oxygen (and therefore with the forma- 

 tion of water) into combinations analogous to the amides, to which 

 the term anilides has been applied. (Gerhardt.*) 



As the elements of cyanate of ammonia, immediately after they 

 are brought together, group themselves in a different manner and 

 form urea, so cyanic acid and aniline do not form a simple salt, but 

 a body, from which neither aniline nor cyanic acid can be again 

 obtained, namely, aniline-urea, C 14 H 8 N 2 O 2 . (Hofmann.t) 



Aniline may so assimilate cyanogen that the latter may be 

 regarded as an adjunct, the newly-formed body, cyaniline, entirely 

 retaining its basic properties. (Hofmann.J) 



Aniline probably affords stronger evidence than any other body 

 yet examined in reference to this point, in favour of the substitution 

 theory, since not merely one, but several of its equivalents of 

 hydrogen, may be replaced by chlorine, bromine, iodine, or hypo- 

 nitric acid, without the group of atoms entirely losing its basic 



* Journ. do Pharm. et deChim. 1845, Juill. pp. 53-56. 



t Quart. Journ. of the Chem. Soc. of Lond. 1848. Vol. i., pp. 159-174. 



| Ann. d. Ch. u. Pharm. Bd. 57, S. 247 ff. 



