IODINE  FROM  THE  ASHES  OF  SEA-WEEDS.  539 
be  luted  with  fine  clay ;  in  the  centre  of  this  dome  a  circular 
hole  should  be  left  about  18  inches  diameter,  with  a  flange  round 
its  edge,  into  which  a  small  dome  should  fit,  and  be  luted ;  this, 
as  well  as  the  larger,  should  have  handles  soldered  on,  so  that 
they  could  be  easily  lifted  off  when  required;  in  the  smaller 
dome  two  flanged  holes  are  made  to  receive  the  bent  ends  of  the 
leaden  arms,  which  are  to  convey  the  fumes  of  the  iodine  into 
the  receivers  or  condensers.  These  arms  are  made  of  moderately 
thin  lead  soldered  in  the  form  of  a  tube ;  they  should  be  about 
Z i  inches  in  diameter,  and  their  bent  elbow  luted  into  the  flanged 
holes  in  the  small  dome.  They  should  also  at  the  top  of  the 
elbow  have  a  small  leaden  plug  like  the  stopper  of  a  vial,  which 
can  be  taken  out  occasionally  by  the  operator  to  judge  of  the 
process  of  sublimation.  The  arms  should  be  long  enough  to  clear 
the  edge  of  the  stile  about  six  or  eight  inches,their  ends  being  there 
introduced  into  the  receivers.  These  latter  are  large  earthen- 
ware carboys  laid  on  their  sides,  and  having  a  neck  and  hole  in 
the  bottom.  The  end  of  the  leaden  arm  is  connected  with  the 
first  receiver  by  having  its  end  thrust  about  two  inches  clear  into 
the  hole  in  the  bottom  ;  the  neck  of  this  receiver  is  fitted  into 
the  bottom  of  the  next,  and  so  on  through  the  series,  which 
should  consist  of  eight  or  ten  placed  in  two  rows,  side  by  side,  on 
a  wooden  frame ;  the  two  arms  from  the  stile  leading  the  iodine 
as  it  sublimes  into  them,  where  it  condenses.  All  the  places 
where  the  joinings  are  should  be  carefully  luted  with  fire  clay. 
Having  thus  described  the  stile  and  its  accessories,  let  us  see 
how  it  is  to  be  wrought. 
The  stile  should  be  filled  with  the  neutralized  ley  up  to  within 
six  inches  of  the  brim;  the  larger  dome  not  being  moved  for  this 
purpose,  the  hole  for  the  smaller  dome  being  large  enough  for 
filling.  A  fire  is  now  kindled  in  the  small  furnace  of  the  boiler, 
and  the  liquid  heated  up  until  the  leaden  dome  feels  pretty  hot. 
Never  having  used  a  thermometer  to  determine  the  heat,  I  can- 
not indicate  the  temperature  nearer  ;  it  must  not,  however,  at 
this  point  reach  a  boiling  heat.  The  smaller  dome  is  now  to  be 
luted  on,  the  arms  are  luted  into  their  respective  places  in  this 
dome,  and  into  the  ends  of  the  receiver,  and  the  oxide  of  man- 
ganese is  now  to  be  added.  The  quantity  for  a  stileful,  the  size 
indicated,  is  from  60  to  80  lbs.  finely  ground ;  it  is  introduced 
