556  Iodine  of  Potassium  from  Kelp.  \%lTiFim*' 
one  another;  and  crystalline  salts  apparently  are  subject  to  such  in- 
fluence under  some  law  connected  with  the  complexity  of  their  crys- 
talline form.  Again,  two  colloid  salts,  as  the  hydrates  of  alumina 
and  of  ferric  oxide,  scarcely  admit  of  complete  separation. — London 
Chem.  News,  Oct.  11,  1872. 
NEW  PROCESS  FOR  THE  MANUFACTURE  OF  IODIDE  OF  PO- 
TASSIUM FROM  THE  MOTHER- LIQUORS  OF  KELP  * 
By  E.  Sokstadt. 
This  process  consists  in  converting  the  alkaline  iodides,  contained 
in  the  mother-liquors  from  kelp,  into  iodates  ;  precipitating  the  iodic 
acid  by  a  soluble  barium  salt ;  heating  the  precipitate  with  solution 
of  sulphate  of  potassium,  which  gives  iodate  of  potassium  in  solution  ; 
drying  up  and  melting  the  iodate  of  potassium  solution,  and  crystal- 
lizing the  solution  of  the  melted  iodide  of  potassium  thus  obtained. 
The  conversion  of  iodides  into  iodates  in  the  mother-liquors  is  ef- 
fected by  one  of  the  following  processes.  But  it  is  advisable,  first,  to* 
partially  or  completely  precipitate  the  sulphuric  acid  from  the  mother- 
liquor  by  solution  of  chloride  of  barium  or  other  suitable  barium  salt, 
as  thus  silicic  acid,  if  present,  and  other  impurities  are  separated,  and 
the  precipitate  afterwards  obtained  of  iodate  of  barium  is  more  man- 
ageable. The  mother-liquor  is  then,  after  separation  of  the  precipi- 
tate, melted,  to  destroy  organic  matter.  The  melted  mass  is  dissolved 
in  water,  and  the  solution,  after  separation  from  the  residue,  is,  if  in- 
tended for  treatment  by  any  of  the  processes  except  the  last  under- 
mentioned, rendered  alkaline  by  addition  of  a  caustic  or  carbonated 
alkali,  to  such  extent  that  the  liquid  may  contain,  for  each  atom  of 
an  iodide  in  it,  five  atoms  of  a  caustic  alkali,  or  ten  atoms  of  a  car- 
bonated alkali.  The  liquid  thus  prepared  may  then  be  treated  by 
any  of  the  following  processes  for  conversion  of  the  iodide  in  it  into* 
iodate. 
(1)  .  Chlorine  is  passed  through  the  liquid  until  the  whole  of  the- 
iodide  is  transformed  into  iodate,  but  no  longer. 
(2)  .  Solution  of  a  permanganate  is  added  until  a  slight  permanent 
coloration  of  permanganate  remains.  The  liquid  is  then  separated 
from  the  manganese  precipitate,  which  latter  may  be  furnaced  with 
soda,  or  with  soda  and  nitre,  to  reform  permanganate  for  another 
operation. 
*  Patent  No.  1054,  April  10, 1872. 
