456 
CHEMICAL  RESEARCHES  ON  SUGAR  REFINING-. 
ready  been  given  in  the  Chemical  News  (xvii,  56)  by  Brush  and 
Rodman. 
1.  Fe4  12HO 
2.  Fe40  10HO 
3.  Fe402  8HO 
4.  Fe403  6HO 
5.  Fe404  4HO 
6.  Fe405  2HO 
7.  Fe406 
In  the  above  formulas,  No.  1  represents  two  molecules  of  ferric 
hydrate  ;  Church  found  a  stalactite  of  true  ferric  hydrate,  native, 
in  Cornwall,  and  Wittstein  gives  a  similar  formula  to  fresh  arti- 
ficial ferric  hydrate.  No.  2  is  the  only  oxyhydrate,  in  this  series, 
still  unknown,  unless,  indeed,  Haughton's  Kilbride  mineral  con- 
tains this  body.  No.  3  is  brown  iron  ore  from  the  Hiittenrode 
Hartz.  No.  4  is  the  formula  of  a  limonite  and  of  artificial  ferric 
hydrate  altered  by  age — described  by  Wittstein  as  having  a 
crystalline  structure.  No.  5  is  the  mineral  gothite,  and  also  the 
dried  oxyhydrate  commonly  used  in  pharmacy.  No.  6  is  turgite, 
hydro-hsematite,  or  the  mineral  from  Salisbury,  Conn.,  analyzed 
by  Brush  and  Rodman.  No.  7  represents  two  molecules  of  ferric 
oxide. — Lond.  Chem.  News,  June  26,  1868. 
CHEMICAL  RESEARCHES  ON  SUGAR  REFINING. 
By  M.  Emile  Monnier. 
If  sulphurous  acid  gas  is  conducted  into  a  chamber  containing 
coarse  sugar,  the  latter  is  promptly  bleached,  and  about  three- 
fourths  of  the  coloring  matter  are  entirely  destroyed,  whilst  the 
sugar  undergoes  no  change  whatever  in  composition.  After  this 
treatment  the  sugar  smells  strongly  of  sulphurous  acid,  which 
presents  no  inconvenience  in  the  process  of  refining.  To  bleach 
sugar  in  this  manner,  for  1000  parts  by  weight  of  sugar  about 
four  parts  of  sulphur  must  be  burnt,  and  the  gas  conducted  into 
the  chamber.  When  the  operation  is  once  set  going,  the  propor- 
tion of  sulphur  may  be  notably  diminished.  The  sulphur  is  con- 
verted into  gas  by  combustion  in  a  little  furnace  placed  at  the 
side  of  the  chamber.  When  the  action  is  complete,  the  sugar  is 
dissolved  in  water,  and  its  sulphurous  acid  neutralized  by  a  small 
