'^^^jln^iSr*™ }       Gleanings  from  the  Foreign  Journals.  15 
Ibid.,  No.  22,  1880,  from  Rundschau  fur  d.  Interesse  d.  Pharm.  Ch., 
■etc.,  1880,  p.  546. 
On  the  Examination  of  Reduced  Iron.    By  O.  Wilner,  of 
.Stockholm. — Upon  the  basis  of  a  large  number  of  researches  executed 
*in  the  Pharmaceutical  Institute  of  Stockholm,  fully  detailed  in  No.  15 
of  the    Farniaceutisk  Tidskrift,"  August,  1880,  the  author  makes  the 
following  series  of  practical  deductions  : 
1.  The  amount  of  metallic  iron  in  reduced  iron  can  be  accurately 
■determined  by  treatment  with  mercuric  chloride  and  titration  with 
2)otassium  permanganate. 
2.  If  metallic  iron  is  treated  by  the  aid  of  a  gentle  heat  with  an 
•excess  of  a  concentrated  solution  of  mercuric  chloride,  mercurous  chlo- 
ride and  metallic  mercury  are  separated,  and  the  metallic  iron  passes  as 
ferrous  chloride  into  solution ;  the  ferrous  and  ferric  oxides  which  may 
be- present  remain  undissolved,  and  therefore  do  not  prevent  the  estima- 
tion of  the  amount  of  metallic  iron  in  the  reduced  iron. 
3.  The  amount  of  ferrous  oxide  in  the  preparation  may  be  estimated 
by  treating  the  same  portion  with  hydrochloric  acid,  digesting  the  mix- 
ture in  a  closed  vessel  until  the  finely  divided  ferrous  oxide  becomes 
dissolved,  and  titrating  with  potassium  permanganate. 
4.  The  ferric  chloride  which  is  thus  formed  at  the  same  time  has  no 
appreciable  action  upon  the  precipitated  metallic  mercury  and  mercu- 
rous chloride. 
5.  The  general  acceptance  of  the  opinion  of  Fliickiger  that  reduced 
iron  is  a  mixture  of  metallic  iron  with  ferroso-ferric  oxide,  and  upon 
which  a  method  for  the  estimation  of  the  amount  of  metallic  iron  is 
based,  by  its  conversion  into  oxide  and  weighing  the  latter,  is  considered 
by  the  author  as  incorrect,  the  preparation  being  assumed  to  be  rather 
a  mixture  of  metallic  iron  with  ferrous  and  ferric  oxides  in  varying 
proportions. 
Of  three  specimens  of  reduced  iron  examined  the  following  compo- 
.sition  w^as  determined: 
No.  1.  No.  2  No.,  3. 
Fe,  .  .    74-88  per  ct.       21-35  per  ct.-      34-44  per  ct. 
FeO,      .  .  11-58  12-59  60-38 
FeA,  .  .    11-07  65-41  2*16 
Imx)urities  and  loss,        2-47  0'65  3-02 
All  three  contained  small  amounts  of  substances  insoluble  in  hydro- 
chloric acid,  as  carbon,  quartz,  etc. — Pharm.  Zeitung,  1880,  p.  705. 
