PREPARATION  OF  ARTIFICIAL  COLORING  MATTERS,  ETC.  249 
of  nitrosophenyline.  It  has  the  formula  C^^HqN^O,^.  When 
obtained  as  above,  it  is  a  black,  shining,  substance  ;  when  heat- 
ed, it  fuses  and  decomposes  directly  :  it  is  almost  insoluble  in 
water,  but  freely  soluble  in  alcohol  and  acids.  An  alcoholic 
solution  containing  only  0-2  per  cent,  is  so  deeply  colored  that 
by  reflected  light  the  solution  seems  opaque  and  of  an  orange 
red. 
Concentrated  hydrochloric  acid  and  dilute  sulphuric  and 
nitric  acids  form  magnificent  crimson  red  solutions  with  nitro- 
sophenyline, which  is  precipitated  from  them  again  unchanged 
by  alkalies. 
Binitrobenzole  treated  with  an  alcoholic  solution  of  sulphide 
of  ammonium  is  at  first  converted  into  nitraniline, — 
C,,H,(NO),N=Ci,H,N,0„ 
that  is  to  say  aniline,  in  which  one  equivalent  of  hydrogen  is 
replaced  by  one  of  nitrous  vapor.    Nitraniline  crystallizes  in 
yellow  needles  which  stain  the  epidermis  like  picric  acid. 
There  is  a  second  aniline  compound  in  which  two  equivalents 
of  hydrogen  are  replaced  by  two  equivalents  of  nitrous  acid, 
dinitraline  —  Cj2H.2(N02)N.  By  the  prolonged  action  of  sul- 
phuretted hydrogen  and  ammonia  on  nitraniline  and  dinitrani- 
line  two  new  bases  are  produced, — azophenylamine  and  nitrazo- 
phenylamine.  The  following  equations  express  the  re-actions 
which  take  place  : — 
Ci2HgN,0,+6HS=  C12H3N2+4HO+6S 
Nitraniline.  Azophenylamine. 
Ci,H,N303+6HS=  C,,H.N30,+4HO+6S 
Dinitraniline.  Nitrazophenylamine. 
The  second  of  these  bases,  nitrazophenylamine,  merits  some 
attention,  inasmuch  as  it  ofi'ers  some  resemblance  to  the  colored 
derivatives  of  aniline.    It  is  prepared  in  the  following  manner  :* 
Dinitraniline  is  boiled  for  two  hours  with  a  great  excess  of  sul- 
phide of  ammonium.    The  liquid  soon  becomes  dark  red  ;  the 
yellow  crystals  of  dinitraniline  disappear,  and  are  succeeded  by 
a  network  of  delicate  needles,  of  a  deep  red  color,  the  quantity 
of  which  is  much  increased  on  cooling  the  liquid  after  the 
*Gerhardt,  CJiimie  Organ,,  iii.  p.  105  ;  Gmelin's  Handbook,'^  xi. 
p.  294. 
