ON  SULPHATE  OF  ANILIN. 
297 
the  receiver  and  the  flask,  the  last  to  be  left  loosely  stopped 
with  cotton,  the  acetic  acid  is  poured  in  through  the  tubulure, 
which  should  be  closed  and  tied.  Reaction  soon  commences 
without  the  application  of  heat  and  becomes  rapid,  with  quick 
rise  of  temperature  and  rapid  ebullition,  and  a  large  portion  of 
the  products  will  be  lost  should  the  refrigeration  be  imper- 
fect. The  spontaneous  distillate  consists  of  anilin,  acetate  of 
anilin,  and  a  little  undecomposed  nitro-benzole.  When  the  re- 
tort has  cooled  these  are  returned  to  it  from  the  receiver,  and  a 
careful  sand  bath  heat  applied  until  the  residue  in  the  retort  is 
dry. 
The  distillate  is  now  mixed  with  an  excess  of  a  solution  of 
caustic  potassa,  when  the  hydrated  anilin  is  separated  and  rises 
to  the  surface,  whence  it  is  to  be  removed  and  dried.  It  is  suffi- 
ciently pure  for  medical  purposes  and  yields  a  soft  mass  of 
crystals  when  mixed  with  sulphuric  Or  muriatic  acid,  which  dis- 
solve in  water.  By  this  method,  Bechamp  states  that  in  seve- 
ral trials  he  obtained  as  much  anilin  as  equalled  three-fourths 
of  the  nitro-benzole  employed,  and  at  a  cost  (in  1855)  of  two 
dollars  a  pound.     (Chem.  Gaz.  vol.  13th,  page  85.) 
Anilin  when  pure  is  a  colorless,  thin  oily  liquid,  but  as  usual- 
ly seen  in  commerce  has  a  more  or  less  red  color,  sometimes  as 
dark  as  bromine,  arising  from  oxidation  in  part,  and  also  from 
impurities.  Its  odor  is  peculiar  ;  when  pure  not  disagreeable, 
but  often  modified  by  other  products  so  as  to  remind  one  of  coal 
oil.  Its  density  is  stated  as  variously  as  1-20  and  1-28.  Its 
taste  is  acrid  and  pungent;  it  is  but  slightly  soluble  in  water 
and  does  not  crystallize  at  4°  below  zero,  F.  It  boils  at  860° 
F.  and  distills  unchanged.  It  is  a  powerful  base,  forming  salts 
with  a  strong  tendency  to  crystallize.  Its  basic  power  enables 
it  to  decompose  the  salts  of  iron,  zinc,  alumina,  &c,  like  ammo- 
nia. It  does  not  change  the  color  of  reddened  litmus,  or  red- 
dened turmeric,  but  changes  dahlia  blue  to  green.  It  oxidizes 
easily  even  under  water,  turning  yellow,  and  then  reddish,  be- 
coming resinous.  It  is  easily  characterized  by  instantly  strik- 
ing a  deep  violet  blue  by  contact  with  chlorinated  lime  or  other 
hypochlorites.  It  exerts  no  poisonous  action  on  dogs.  Eight 
grains  introduced  with  a  drachm  and  a  half  of  water  into  the 
stomach  of  a  rabbit  caused  strong  clonic  cramps,  then  labo. 
