PREPARATION  AND  PURIFICATION  OF  BENZOLE. 
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and  the  same  refrigerator)  having  been  heated  to  clear  redness, 
a  continuous  "thread  of  heavy  oil  is  poured  into  them  by  means 
of  a  syphon  attached  to  the  exterior  part  of  each  retort,  and  ter- 
minating high  up,  with  a  funnel  to  receive  the  oil  from  a  tap  con- 
nected with  the  reservoir  above. 
As  the  oil  flows  into  the  retorts,  it  is  rapidly  affected  by  the 
high  temperature,  which  modifies,  at  least,  to  a  certain  extent, 
its  composition  and  its  properties.  The  result  is,  more  or  less, 
graphitous  or  light  charcoal,  which  remains  in  the  retort,  and 
more  or  less  volatile  oils  and  gaseous  hydrocarbons. 
As  the  volatile  and  gaseous  products  penetrate  into  the  water 
chamber,  a  first  separation  is  effected,  then  in  this  chamber  are 
condensed  the  heavy  and  little  altered  oils,  which  must  afterwards 
be  again  passed  through  the  red  hot  retort ;  the  more  volatile 
products  also  traverse  the  refrigerator,  where  are  condensed  the 
light  oils  produced  in  the  operation,  which,  rectified  in  an  ordi- 
nary alembic,  furnish  light  volatile  colorless  oils,  rich  in  ben- 
zole. 
For  the  more  perfect  purification  of  benzole  (or  benzine),  I 
propose  taking  advantage  of  its  property  of  solidifying  under 
the  influence  of  cold,  taking  the  form  of  flakes,  grouped  like  fern 
leaves,  or  in  crystalline  masses  similar  to  camphor,  melting  only 
at  8°*5  above  0°.  For  this  purpose  we  cool  the  rough  benzine 
to  — 15°  in  M.  Carre's  refrigerator,  strongly  and  rapidly  press 
the  benzine  crystals  still  impregnated  with  other  liquid  hj^-o car- 
bides, and  thus,  with  the  greatest  ease,  we  obtain  crystalline  ben- 
zine, which,  again  melted  and  once  more  submitted  to  the  same 
treatment,  gives  us  benzine  almost  chemically  pure. 
With  such  a  benzine  a  pure  nitro-benzine  may  be  obtained, 
very  useful  in  perfumery,  and  with  which  perfectly  pure  aniline 
may  be  prepared. 
But  we  doubt  whether,  in  the  manufacture  of  artificial  coloring 
matters,  the  preparation  of  chemically  pure  benzine,  nitro-ben- 
zine, and  aniline,  is  of  so  much  practical  importance  as  might 
have  been  expected ;  unless,  indeed,  we  can  at  the  same  time 
offer  to  manufacturers  toluol,  nitrotoluol,  toluidine,  and  homolo- 
gous products,  so  that  they  can  operate  on  mixtures  giving  the 
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