Am  jour.  Pharm.  I 
July,  1877  J 
Note  on  Dialyzed  Iron. 
343 
The  first  paper  on  this  subject  deserving  notice  is  one  by  John  M. 
Ordway,  entitled  kC  Examination  of  the  soluble  basic  sesquisalts," 
which  was  published  in  the  "Am.  Journal  of  Science  and  Arts,"  2d 
ser.,  xxvi,  p.  197  (1858),  and  in  which  the  following  language  is  used  : 
"  Time  is  a  very  important  element  in  the  production  of  the  highly 
basic  compounds.  One  may  easily  be  deceived  as  to  when  the  hydrate 
ceases  to  be  dissolved,  and  may  set  down  as  opaque  that,  which  by 
longer  digestion  becomes  quite  transparent.  Bv  successive  steps  we 
get  pretty  easily  as  far  as  Fe2Clc,  1 1  Fe2Os,  and  in  the  course  of  several 
weeks  I  have  gone  as  high  as  Fe2Cl6,23Fe203," 
The  next  important  paper  is  by  Bechamp  (1859),  published  in 
"Annales  de  Chimie  et  de  Physique,"  3d  ser.,  Ivii,  296,  which  in  the 
main  corroborates  the  statements  of  Ordway,  but  gives  the  most  basic 
compound  obtained  Fe2Cl6,  20Fe2O3.  In  both  cases  the  solutions  of 
the  normal  salt  were  digested  with  ferric  hydrate. 
Th.  Graham's  celebrated  essay  on  the  diffusion  of  liquids  ("  Phil. 
'  Trans.,"  1 86 1 ,  1 83)  announces  the  following  results  :  "  If  recently  pre- 
cipitated ferric  hydrate  or  carbonate  of  ammonium  is  added  to  an  aqueous 
solution  of  ferric  chloride,  as  long  as  the  precipitates  are  redissolved, 
and  if  the  dark-red  solution  thus  obtained,  containing  from  4  to  5  per 
cent,  of  solid  matter,  is  subjected  to  dialysis,  mainly  muriatic  acid  will 
pass  through  the  septum  upon  which,  after  19  days,  remains  a  red  liquid 
containing  for  98*5  parts  of  oxide  1*5  part  of  muriatic  acid.  It 
remains  liquid  for  20  days  and  then  gelatinizes,  separating  ferric 
hydrate.  A  similar  solution  of  colloidal  ferric  hydrate  may  be  obtained 
by  dialysis  of  ferric  acetate,  and  contains  6  parts  of  acetic  acid  to  94 
parts  of  ferric  oxide." 
Calculating  Graham's  results  as  an  oxychloride,  the  formula  Fe2Cl6, 
95Fe203  would  be  obtained,  which  seems  to  be  hardly  probable.  At 
the  same  time,  it  must  be  remembered,  that  none  of  the  so-cailed 
soluble  oxide  of  iron  has  as  yet  been  obtained  free  from  acid.  Gra- 
ham's figures,  I  believe,  are  the  lowest  thus  far  observed,  and  the 
solution  was  not  permanent,  but  gelatinized  spontaneously.  It  must 
therefore  be  granted  that  any  permanent  solution  of  so-called  soluble 
oxide  of  iron  must  contain  notable  quantities  of  acid  ;  and  within  the 
past  year  such  has  been  proven  by  Hager  to  be  the  case  for  several 
European  preparations  sold  as  oxide  of  iron. 
The  behavior  of  these  solutions  is  quite  curious  and  apt  to  mislead, 
