ON  SODIUM  AND  ITS  MANUFACTURE.  57 
ON  SODIUM  AND  ITS  MANUFACTURE. 
By  William  Bkatson. 
Having  for  some  years  given  considerable  attention  to  the  pro- 
duction of  the  alkaline  metals,  I  have  succeeded  in  obtaining 
them  (particularly  sodium)  in  such  quantities,  as  to  show  that  it 
only  needed  the  demand  to  be  created,  and  they  could  be  sup- 
plied in  such  a  way,  as  would  greatly  promote  the  application 
and  extension  of  science  and  the  chemical  arts,  and  it  was  only 
because  that  demand  did  not  appear  to  exist,  that  the  subject 
was  allowed  to  remain  in  comparative  abeyance,  -now  that  such 
interest  has  been  excited  in  the  enlarged  application  of  Mr. 
Wohler's  process,  for  preparing  aluminium  by  means  of  sodium, 
chiefly  through  the  exertion  of  M.  St.  Clair  Deville,  it  may  not 
be  uninteresting  to  indicate  the  means  by  which  this  latter  metal, 
sodium,  may  be  extracted  by  enlarged  and  improved  processes, 
which  I  have  been  led  to  employ  for  some  time  past. 
The  retorts,  in  which  the  mixture  of  carb.  soda  and  coke  has 
been  heated,  have  been  chiefly  of  maleable  iron  ;  but,  as  it  is 
difficult  to  obtain  these  of  a  large  size,  retorts  of  earthenware  or 
fire-clay  have  been  used  with  success,  and  probably  a  fire-clay 
retort,  with  a  lining  or  trough  of  malleable  iron,  will  be  found  to 
be  the  best  form  of  distilling  apparatus,  though  with  great  care 
cast-iron  retorts  may  yet  be  employed  with  advantage.  The 
principle  improvement  which  I  have  effected,  and  which  is  now 
engaging  the  attention  of  M.  Deville,  consists  in  making  the 
process  continuous ;  so  that  the  retort  is  maintained  at  nearly  a 
uniform  temperature,  and  only  requires  the  introduction  of  a 
fresh  charge  when  the  previous  one  has  been  worked  off.  If  the 
materials  are  properly  proportioned,  the  retort  becomes  nearly 
empty  at  the  termination  of  each  distillation  ;  or,  if  an  excess  of 
carbon  remains  in  the  retort,  it  is  available  in  the  following  opera- 
tion, so  that  in  this  way  one  retort  has  been  kept  in  full  action 
for  a  week,  and  sometimes  for  nearly  a  second  week,  without  in- 
terruption. As  soon  as  one  distillation  is  completed,  and  the 
condenser  removed,  a  fresh  charge  of  soda  and  carbon  is  intro- 
duced into  the  retort,  through  the  same  tube  as  emits  the  sodium, 
by  means  of  a  long  semi-circular  scoop,  and  the  retort  being 
nearly  filled,  the  new  distillation  commences  in  a  short  time,  and 
