IODINE  FROM  THE  ASHES  OF  SEA-WEEDS. 
533 
Kelp  Waste. 
Scotland  and  Ireland;     4,000  tons. 
France,     .       .       .     1,000   "       5000  tons.    $1.00  per  ton.  5,000 
$469,901) 
Four  hundred  sixty  nine  thousand  nine  hundred  dollars.  And 
this  large  sum,  the  result  of  a  trade  in  an  article  discovered  only 
in  1812,  and  not  yet  in  anything  like  general  use  as  a  remedial 
agent  more  than  a  single  generation  ;  one  of  the  many  inestima- 
ble boons  presented  to  suffering  humanity  in  the  progress  of 
chemical  science. 
We  now  proceed  to  consider  the  modes  adopted  for  the  manu- 
facture of  iodine  from  kelp ;  and  first  in  order  as  being'the  most 
important  in  view  of  the  object  of  this  paper,  is 
The  preparation  of  the  Raiv  Material  or  Kelp. 
All  the  deep  sea  plants  are  more  or  less  rich  in  iodine  in  con- 
tradistinction to  those  which  grow  above  low-water  mark  ;  as  a 
general  rule  those  sea  plants  which  are  fully  exposed  to  the 
action  of  the  sun  and  air  by  recession  of  the  tide,  are  unfit  for 
the  preparation  of  kelp  for  iodine  making;  they  are  charac- 
terized by  being  possessed,  in  a  greater  degree,  of  salts  of  soda 
than  those  which  draw  their  sustenance  entirely  from  the  ocean, 
these  latter  being  extremely  rich  in  potash  salts  and  iodine  as 
compared  with  the  former,  but  varying  in  this  respect  consider- 
ably from  each  other.  To  those,  then,  who  may  essay  the  pro- 
duction of  the  most  profitable  kelp  for  the  iodine  manufacture, 
we  would  say,  in  a  word,  reject  ail  those  plants  which  may  be  pro- 
cured by  cutting  them  from  the  rocks  at  low  water,  as  not  worth 
the  trouble  and  expense  of  preparing,  and  trust  to  the  mixed 
kinds  of  deep  sea  plants  which  are  abundantly  thrown  up  on  the 
beaches,  after  the  storms  have  torn  them  from  the  submerged 
rocks.  The  best  kind  of  sea  plant  for  the  purpose  is  the  tangle, 
or  Palmata  digitata,  or  lieach,  as  the  Irish  call  it.  This  is  a 
plant  growing  from  one  long  thick  stalk,  with  branches  about 
three  inches  in  breadth,  with  a  smooth  and  leather-like  appear- 
ance, very  greasy  and  slimy  to  the  touch ;  when  cast  ashore  in 
heaps  it  has  a  greenish  yellow  tinge.  Wherever  this  is  plentiful, 
a  rich  kelp  is  easily  prepared. 
