CARBON  BISULPHIDE.
Fornmia^  CS2.
Molecular  Weighty  ISSl'


Carbon  disulphide  was  discovered  by  Lampadius  of  Freiburg  in  1 796
while  heating  pyrites  with  charcoal.  It  is  prepared  by  passing  the
vapors  of  sulphur  over  coke  or  charcoal  which  has  been  heated  to  a
cherry-red  in  retorts  of  cast-iron  or  earthenware.
Purification  consisting  in  removing  uncombined  sulphur,  hydrogen
sulphide,  sulphur  dioxide,  etc.,  is  accomplished  by  washing  with  milk
of  lime  and  treating  with  salts  of  lead  or  copper  and  finally  redistilling.
The  electrical  process  consists  in  placing  carbon  electrodes  in  the  base
of  a  stack  furnace  filled  with  coke  connected  w^ith  conductive  carbons,
so  that  the  coke  will  be  heated  with  the  electrodes  when  the  current
is  turned  on.  The  sulphur,  which  is  fed  in  below,  is  vaporized  and  car-
ried up  through  the  glowing  coke.     The  reactions  involved  are  the  same.
Physical  Properties. — Carbon  disulphide  is  a  colorless,  mobile,
strongly-refracting  liquid,  of  specific  gravity  of  1.256  to  1.257  ^^  25°,
which,  as  it  comes  in  commerce,  usually  has  a  fetid  odor,  due  to  various
sulphur  impurities,  but  when  purified,  is  of  a  mild  ethereal  odor.  It
is  soluble  in  about  526  parts  water,  mixes  in  all  proportions  with  absolute
alcohol,  ether,  chloroform,  and  the  fixed  and  volatile  oils.  It  boils  at
46-47°,  solidifies  at  — 116°  and  melts  at  — 113°.  The  vapor  of  carbon
disulphide  is  very  inflammable,  taking  fire  in  the  air  at  149®;  this  may


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CARBON  AND  SULPHUR.  293

be  qflfected  by  introducing  a  heated  glass-rod  into  its  vapors.  Carbon
disulphide  is  the  best  solvent  for  sulphur,  phosphorus,  rubber,  fats,
iodine,  etc.,  the  latter  dissolving  with  an  intense  violet  color.  Traces
of  iodine  can  be  more  readily  detected  by  its  color  imparted  to  this
solvent,  than  through  the  iodide  of  starch  reaction.
