ON  ALKALINE  IODIDES  AND  BROMIDES. 
293 
to  the  mixture,  until  the  reaction  is  no  longer  produced.  Then 
filter  while  hot  into  a  porcelain  dish,  wash  the  precipitate  on  the 
filter  with  some  hot  water,  add  the  washings  to  the  filtered  solu- 
tion, and  evaporate  to  the  point  of  crystallization,  or  to  dryness 
when  the  salt  is  to  be  granulated  by  stirring  after  crystalliza- 
tion has  begun. 
SECOND  METHOD. 
Take  of  Bicarbonate  of  Potassa        400  parts. 
Iodine  508  " 
Iron  in  filings  112  «< 
Water  a  sufficient  quantity. 
Place  the  bicarbonate  of  potassa,  with  three-fourths  of  the 
iodine,  and  one  half  of  the  iron  and  sufficient  water,  into  a  flask  or 
porcelain  dish,  and  stir  up  until  the  salt  is  dissolved.  In  the 
mean  time  prepare  in  another  glass  vessel  a  solution  of  iodide  of 
iron  from  the  remainder  of  the  iodine  and  iron  and  sufficient 
water  :  add  this,  sediment  and  solution,  to  the  alkaline  mixture, 
stir,  boil  up,  test,  and  proceed  as  above. 
[The  latter  method  seems  preferable  for  larger  quantities ; 
the  resulting  iodide  of  potassium  should  come  within  a  trifle  of 
the  calculated  amount.] 
Iodide  of  Sodium, 
Take  of  crystallized  Carbonate  of  Soda,    572  parts 
Iodine,  508  " 
Iron,  112  " 
Water,  a  sufficient  quantity. 
Proceed  precisely  as  above.  There  is  generally  a  slight  excess 
of  carbonate  of  soda,  owing  to  the  efflorescence  of  the  crystals, 
which  is  remedied  by  the  addition  of  a  small  quantity  of  iodine 
or  iodide  of  iron  in  solution.  The  filtered  solution  is  best  eva- 
porated to  dryness  and  granulated,  on  account  of  the  deliques- 
cent properties  of  the  salt. 
Iodide  of  Lithium. 
Take  of  Carbonate  of  Lithia,     112  parts 
Iodine,  381  « 
Iron  in  filings,  112  " 
Water,         a  sufficient  quantity. 
Place  the  carbonate  of  lithia,  rubbed  fine,  together  with  the 
