PRODUCTION  OF  IODINE  AND  BROMINE. 
429 
the  trade  declined.  But  the  discovery  of  iodine  in  the  mother 
liquors  of  kelp  salts,  somewhat  revived  the  manufacture, — and 
it  is  to  this  source  alone  that  the  total  supply  of  iodine  in  com- 
merce is  due.  The  high  price  stimulated  the  business,  and  in 
this  country,  in  a  few  places  in  New  England,  iodine  factories 
were  established.  These  latter,  however,  were  soon  abandoned, 
the  weed  upon  our  coast  being  of  poor  quality.  The  process  of 
separating  the  iodine  is  exceedingly  simple,  being  nearly  analo- 
gous to  that  for  the  isolation  of  chlorine.  The  ashes  are  leached 
with  water,  and  the  various  crystallizable  salts  of  potash  and 
soda  are  separated  by  concentration.  Carbonates,  sulphates,  and 
chlorides  of  potash  and  soda  are  thus  removed,  leaving  in  solu- 
tion sulphite,  hyposulphite,  and  some  carbonate  of  soda,  together 
with  the  iodides  and  bromides.  By  the  addition  of  sulphuric  acid 
the  first  three  salts  are  decomposed,  and  the  sulphate  of  soda 
produced  is  removed  by  crystallization.  The  concentrated 
mother-liquor  is  acidulated  with  sulphuric  acid,  and  after  the 
addition  of  binoxide  of  manganese,  the  iodine  and  bromine  dis- 
tilled off.    The  reaction  may  be  represented  thus : 
NaI+Mn02+2(HO,S03)=r::.NaO,S03+MnO,S03+I. 
The  bromine  of  commerce  was  derived  mostly  from  salines 
until  the  salt  mines  of  Stassfurt  were  opened ;  the  Schoenebeck 
salt  springs,  near  Magdeburg,  producing  the  greater  part  of  the 
supply  for  Germany.  The  method  of  manufacture  is  similar  to 
that  followed  in  the  separation  of  iodine. 
Upon  opening  the  mines  of  Stassfurt,  bromine  was  found  in 
the  mother-liquors  in  considerable  quantities,  and  at  present  the 
principal  part  of  the  European  product  is  derived  from  this 
source.  As  high  as  300  grns.  per  gallon  has  been  obtained 
from  these  mother-liquors.  Although  but  two  or  three  of  the 
manufactories  at  this  place  have  economized  this  substance,  the 
price  of  bromine  has  greatly  decreased  during  the  last  five  years. 
This  decrease  has  been  hastened  by  the  large  production  of  bro- 
mine in  the  United  States. 
Although  the  amount  of  bromides  in  the  Saratoga  waters  is 
considerable,  3^et  the  comparatively  limited  flow  of  water  here 
and  the  large  consumption  of  these  waters  for  medicinal  pur- 
