158  MANUFACTURE  OF  SULPHIDE  OF  CARBON. 
cost  50  francs  (£2)  ;  in  1848,  M.  Deiss  manufactured  and  sold 
it  at  8  francs  per  kilo.,  and  now  it  may  be  had  wholesale  at  50 
centimes  the  same  quantity.  The  apparatus  now  in  use  consists 
of  vertical  retorts  made  of  the  same  kind  of  clay  as  is  in  use 
for  glass-pots  ;  these  retorts  are  1*8  metre  high  by  0*50  internal 
diameter,  they  are  lined  internally  with  a  glaze  composed  of  130 
parts  of  flint  glass,  20  parts  of  carbonate  of  soda,  and  12  parts 
of  boracic  acid  fused  together,  and  next  pulverised  and  painted 
on  the  inside  of  the  retorts  with  gum  water  (at  the  first  heating 
of  the  retorts  this  mixture  yields  a  glaze  which  entirely  closes 
the  pores  of  the  material,  thus  preventing  escape  of  vapors  and 
gases) ;  four  of  these  retorts  are  set  in  one  oven  made  of  brick- 
work, and  are  heated  by  a  properly  constructed  furnace  ;  the 
retorts  are  provided  with  the  necessary  tubes  for  the  abduction 
of  the  vapors  of  the  sulphide  of  carbon,  and  the  introduction  of  the 
charges  of  sulphur  and  charcoal ;  the  operation  once  commenced 
is  continuous,  since  the  retorts  last  for  at  least  six  months;  the 
consumption  of  sulphur  per  retort  amounts  to  125  kilos,  in  24 
hours,  introduced  in  charges  of  155  grms.  each,  every  three 
minutes  time  ;  the  vapors  of  the  sulphide  of  carbon  are  collected 
and  condensed  in  vessels  made  of  zinc  or  sheet-iron,  and  shaped 
like  flattened  down  casks,  and  entirely  covered  over  with  cold 
water  constantly  refreshed,  while  the  contrivance  is  so  arranged 
as  to  keep  the  sulphide  under  water  also  (its  specific  gravity  is 
1*265,  and  its  boiling  point  45°).  The  most  suitable  tempera- 
ture for  this  manufacture  is  bright  red  heat ;  the  raw  liquid  ob- 
tained has  to  be  re-distilled,  and  this  operation  is  conducted  in 
large  iron  vessels,  which  contain  some  5000  kilos,  at  the  same 
time  and  communicate  with  six  worm  condensers  ;  steam  is  used 
for  heating  by  means  of  a  serpentine-coiled  set  of  pipes,  and  the 
liquid  is  heated  to  48°  ;  near  the  end  of  the  distillation  the  tem- 
perature is  raised  to  100°,  in  order  to  drive  ofi"  a  raw  product 
containing  very  much  sulphur  dissolved ;  in  the  distillatory  ap- 
paratus  some  sulphur  remains  ;  which  is  removed  and  again  ap- 
plied ;  it  appears  that  this  industry  has  become  very  extended 
and  is  carried  on  with  great  success  in  France. — Ohem.  News, 
Jan.  7, 1870. 
