26 
ON  EXTRACTUM  FERRI  POMATUM. 
ON  EXTRACTUM  FERRI  POMATUM. 
By  J.  M.  Maisch. 
On  the  continent  of  Europe,  a  preparation  is  officinal  in  most 
Pharmacopoeias,  the  virtues  of  which>  reside  in  the  malate  of  iron 
which  it  contains.  As  many  European  physicians  in  this  country 
habitually  employ  it,  and  neither  the  United  States  nor  any  of 
the  British  Pharmacopoeias  recognize  it,  it  may  perhaps  not  be 
out  of  place  to  say  a  few  words  here  about  the  mode  of  prepar- 
ing it  and  its  medicinaluse. 
Extractum  Ferri  Pomatum,  Extr.  Malatis  Ferri,  or  Ext.  Ferri 
Malici,  is  prepared  by  digesting  one  part  of  iron  with  from  four  to 
sixteen  parts  of  unripe  very  tart  apples,  mashed  to  a  pulp,  or 
their  expressed  juice,  for  the  space  of  several  days,  then  express- 
ing the  mass,  straining  the  liquor  and  evaporating  it  to  the 
consistency  of  an  extract.  In  selecting  a  method  for  its  prepa- 
ration, preference  should  be  given  to  the  employment  of  the  pulp 
of  apples,  as  in  this  case  a  closer  and  more  continued  contact 
with  the  iron  is  insured ;  and  on  occasionally  stirring  the  mass, 
atmospheric  air  is  admitted  and  retained  by  the  pulp,  whereby 
the  oxidation  of  the  iron  is  promoted.  By  most  Pharmacopoeias, 
pure  iron  filings  are  ordered,  but  that  of  Prussia,  probably  fear- 
ing a  contamination  with  copper,  directs  iron  wire,  though  from 
the  presence  of  copper  in  the  filings  it  should  hardly  be  inferred 
that  this  poisonous  metal  could  be  retained  in  solution,  as  the 
large  excess  of  iron  must  precipitate  it  during  its  long  contact 
with  the  pulpy  mass ;  besides,  if  the  neutral  liquor  is  heated  to 
the  boiling  point  the  dissolved  copper  will  be  partly  precipitated  as 
an  insoluble  basic  malate  of  copper.  Such  an  impurity,  however, 
for  the  reason  stated  before,  cannot  occur  if  the  manipulation  has 
been  conducted  right,  and  the  employment  of  otherwise  clean 
iron  filings  is  therefore  admissible.  Another,  and  the  most  im- 
portant point  in  which  the  Pharmacopoeias  differ,  is  the  subse- 
quent treatment  of  the  expressed  and  strained  liquor  during  the 
process  of  inspissation.  While  some  Pharmacopoeias  direct  it  to 
be  conducted  in  an  iron  vessel  to  the  thickness  of  an  extract, 
others  order  to  boil  the  liquor  for  some  time  in  an  iron  vessel, 
strain  it  and  afterwards  evaporate  it  to  the  proper  consistency 
a  porcelain  dish.    By  the  first  of  these  methods  it  is  evident 
