AmMa°rU,ri8^arm'}  Liquor  Ferri,  Per  oxychloride  of  Iron,  etc.  101 
IV.  -274  Fe203+-oi25  Cl=-z646  Fe2Oy+'oi9i  Fe2Cl8=93'3  per  cent.  Fe203-f 
6*7  per  cent.  Fe2Cl3. 
Dr.  Hager's  Liquor  ferri  peroxychlorati,  which  he  prepares  by  dissolv- 
ing the  ferric  hydrate  obtained  from  115  parts  of  ferric  chloride  solu- 
tion in  10  parts  of  the  same  ferric  chloride  solution,  contains,  when 
all  the  ferric  hydrate  is  dissolved,  85  per  cent.  Fe2Oa  and  15  per  cent. 
Fe2Cl3.  No  doubt  a  more  basic  preparation  could  be  realized  by  Dr. 
Hager's  method,  that  is,  by  dissolving  ferric  hydrate  in  ferric  chloride 
solution,  if  the  ferric  hydrate  were  perfectly  pure.  But,  as  his  ferric 
hydrate  always  contains  ammonia,  which  cannot  be  removed  by  wash- 
ing, this  ammonia  forms,  when  the  precipitate  is  added  to  the  ferric 
chloride  solution,  ammonium  chloride,  which  sets  a  limit  to  the  solu- 
tion of  ferric  oxide.  The  basicity  of  this  preparation  stands  in  inverse 
ratio  to  the  quantity  of  ammonium  chloride  in  it. 
Dr.  Wagner,  the  originator  of  dialyzed  iron,  does  not  communicate 
the  method  for  making  his  later  preparation,  the  catalytic  iron,  but 
asserts  that  it  is  not  made  by  dialysis,  and  that  it  takes  three  months  to 
make  it.  To  judge  by  this,  the  supposition  might  not  be  far  from 
wrong,  that  it  is  a  solution  of  a  basic  oxychloride  precipitate,  obtained 
as  above  explained.  The  writer  could  not  obtain  any  of  Dr.  Wag- 
ner's catalytic  iron,  and  therefore  cannot  say  how  much  chlorine  it 
contains  in  proportion  to  the  ferric  oxide  ;  that  it  does  contain  chlorine 
Dr.  Hager  has  fully  proven. 
The  above  experiments  teach  us  that  the  preparation  of  a  perfectly 
pure  ferric  hydrate  is  very  difficult,  almost  impossible,  as  in  one  case 
it  is  apt  to  contain  chlorine,  in  the  other  ammonia.  They  prove  that 
the  precipitate  of  oxychloride  of  iron  is  soluble  in  pure  water,  and  that 
in  its  more  basic  combinations  it  is  only  soluble  when  free  of  saline 
compounds. 
They  likewise  prove  that  a  solution  of  very  basic  oxychloride  can 
be  prepared  without  dialysis,  and  that  the  product  may  be  made  to  con- 
tain a  less  per  cent,  of  chlorine  than  that  found  in  the  best  commer- 
cial sample  of  dialyzed  iron  examined  by  the  writer. 
By  referring  to  the  precipitate  of  experiment  it  becomes  evident 
that  the*  solvent  power  of  ferric  chloride  on  ferric  hydrate  has  a  limit. 
This  indicates  at  the  same  time  that  a  pure  ferric  hydrate  will  not  dis- 
solve, and  that  in  all  the  different  iron  solutions,  whether  they  be  called 
peroxychloride,  dialytic  or  catalytic,  the  ferric  oxide  is  kept  in  solution 
