58 
ON  SODIUM  AND  ITS  MANUFACTURE. 
proceeds  with  the  greatest  regularity  and  success ;  the  sodium 
which  I  have  sent  to  the  Paris  exhibition,  was  prepared  in  this 
way,  and,  as  before  stated,  it  was  only  because  there  seemed  to 
be  no  demand  for  the  metal,  that  it  was  not  prepared  on  an  in- 
dustrial and  extensive  scale  :  perhaps,  as  in  some  other  instances, 
the  supply  may  create  or  excite  the  demand.  In  addition  to  the 
sodium,  it  is  well  known  that  a  large  quantity  of  croconates  and 
other  compounds  of  soda  distil  over  and  are  found  mixed  with 
the  sodium,  and  as  their  separation  is  tedious  in  small  quantities, 
I  have  constructed  a  large  iron  cylinder,  in  which  the  sodium 
and  its  impure  admixtures  are  heated  to  fusion,  below  the  sur- 
face of  naptha  or  camphine,  and  a  piston  or  plunger  being  then 
forced  down  by  a  powerful  screw  or  hydraulic  press,  the  pure 
metal  is  found  in  a  mass  above,  and  the  impurities  in  the  bottom 
of  the  cylinder. 
The  subjoined  figure  will  explain  the  method  of  continuous  dis- 
tillation : — 
(a)  Retort  of  iron,  inside  of  fire-clay.  (6)  Chamber  of  reverberatory 
furnace,  (c)  Eduction  tube,  attached  by  screws  at  (d)  to  the  iron  receiver 
(e),  which  is  made  in  two  parts,  screwed  together,  and  cemented  at  (f), 
the  lower  part  (</),  containing  naptha  or  camphine.  (A)  Tap  supplying 
cold  water,  which  by  means  of  an  external  case  circulates  round  the  con- 
denser (e),  falling  into  the  pan  (P).  is  a  strong  iron  rod,  with  sharpen- 
ed steel  chisel  at  the  end,  for  clearing  out  the  eduction  tube  (c).  (s)  Escape 
tube  for  incondensible  gases. 
Rotherham,  August         1855.  The  Chemist. 
