aniline

[from anil (q.v.)] = amido benzene = amido-benzol = phenylamine = CHN = (CH) N = CH(NH2). H Chem.: Aniline was first obtained by distilling indigo with caustic potash. It occurs in the heavy oils from coal-tar. It is prepared from benzene, C6H6, which is converted into nitrobenzene, C6H2(NO2), by the action of strong nitric acid. The nitrobenzene is reduced to aniline by the action of acetic acid and iron filings, or by sulphide of ammonium. Aniline is the basis of most of the coal-tar colours. It is an oily, colourle , refractive, volatile liquid, boiling at 182°. Its sp. gr. at 0° is 1-036. It solidifies at 8° to a crystalline ma ; when exposed to the air and light, it becomes brown. It is nearly insoluble in water, but di olves in ether, alcohol, and benzene. forms crystalline salts with acids. It does not turn red litmus paper blue. A slight trace of aniline gives a deep purple colour with a solution of bleaching powder. Aniline combines with the iodides of alcohol radicals like amines. The atoms of H united to N in aniline can be replaced by alcohol radicals, as ethyl aniline (C6H5 NH (CH5. It The H in the benzol ring (C6H5) can also be replaced by radicals forming substitution compounds of aniline, of which, when one atom of H is replaced by an atom of Cl or a radical, there can be always three modifications: thus, three modifications of nitro aniline (C6H)(NO2)(NH) are known; also chloraniline, C6H4Cl(NI2)', and bro man i line, C6H4Br(NH2). [See Kekulé's Organic Chem.] M. Langorrois has found that the putrefaction and decomposition of animal matter can be prevented, even when it is exposed to the air, and in an elevated temperature, by the use of small quantities of aniline. ( Medical Pre and Circular, quoted in the Times , May 7, 1873.)