^jut'lmr  }  Solahilitij  of  Sulphxir  in  Coal  Tar  Oil.  267 
lates,  under  the  action  of  high  temperatures,  shows  there  is  room  for 
further  investigation.  Exposed  to  the  heat  from  a  Bunsen's  burner^ 
the  soda  and  potash  salts  exhibited  all  shades  of  color  from  pale  pink 
to  intense  purple  ;  and  afterwards  placed  on  the  glowing  embers  of 
a  bright  fire,  combustion  takes  place  in  a  very  similar  manner  to  the 
old  Pharoah's  serpents,  leaving  an  ash  equally  bulky  and  eccentric. 
— Pharm.  Jour,  and  Trans. ^  April  22,  1871,  p.  845. 
SOLUBILITY  OF  SULPHUR  IN  COAL  TAR  OIL. 
By  C.  Widemann. 
Eugene  Pelouze,  son  of  the  celebrated  chemist  who  died  in  1867^ 
observed  that  the  oils  obtained  in  distilling  the  tar  produced  by  gas 
works,  dissolve  the  largest  amount  of  sulphur  at  a  temperature- 
approaching  their  boiling  point.  As  soon  as  this  temperature  is- 
lowered,  the  sulphur  is  precipitated  in  a  crystallized  form.  This 
property  can  be  used  in  industry  for  the  extraction  of  the  sulphur 
from  the  "  solfatares,"  or  sulphur  ores  coming  from  volcanoes,  and 
especially  in  treating  the  matters  used  for  the  purification  of  common 
street  gas.  According  to  Lanning's  process,  coal  tar  oil  having  dis- 
solved 43  grammes  of  sulphur  at  130°  Centigrade,  and  afterward 
cooled  down  to  15°  Centigrade,  produced  41  grammes  of  crystallized 
sulphur  ;  then  the  same  liquor  heated  and  cooled  alternately,  dis- 
solved and  precipitated  a  new  amount  of  sulphur. 
In  order  to  obtain  the  above  results,  only  the  heavy  oil  of  the  tar 
must  be  used,  costing  from  80c.  to  $1  per  100  lbs.  The  oil  is  retained 
after  every  operation  and  can  be  used  over  again.  This  process  is  a 
great  advantage  over  the  sulphide  of  carbon,  not  only  as  regards  the 
price,  but  also  because  they  can  be  operated  at  a  temperature  below 
their  boiling  point,  which  is  very  high,  thus  doing  away  with  the 
losses  of  evaporation  and  the  great  danger  resulting  from  the  use  of 
sulphide  of  carbon. 
The  mixtures  used  for  purifying  gas,  which  are  lost  after  being  in 
use  a  certain  time,  contain  an  average  of  40  per  cent,  of  sulphur^ 
associated  with  saw-dust,  oxide  of  iron,  and  tar  products.  The 
extraction  of  this  sulphur  could  not  heretofore  be  economically  done 
by  the  processes  known,  but  with  the  process  we  describe  it  can  be 
done.    The  following  is  the  mode  of  treatment : 
The  old  purifying  mixtures  having  been  desiccated  by  exposure  to 
