ON  COMMERCIAL  IRON   BY  HYDROGEN. 
21 
into  the  stomach,  and  cause  unpleasant  eructations  accompanied 
by  the  disagreeable  odor  of  the  gaseous  compounds.  For  the 
above  reasons,  iron  reduced  by  hydrogen  has  been  admitted  into 
various  Pharmacopoeias,  and  the  iron  filings  and  iron  powdered 
by  mechanical  means,  is  now  with  us,  for  internal  exhibition, 
entirely  discontinued. 
It  would  appear  to  be  of  great  importance  to  have  this 
powder  in  a  pure  state;  the  difficulties  which  are  connec:;ed 
with  its  preparation  are  such  as  to  prevent  nearly  all  our 
pharmaceutists  from  making  it  for  their  own  use,  and  to  rely  on 
the  products  as  furnished  by  the  manufacturing  chemists. 
Magnus'  test  for  this  reduced  iron  (Am.  Jour.  Pharm.  1859, 
255)  to  apply  a  lighted  match,  when  it  should  readily  burn  to 
the  sesquioxide,  is  sufficient  to  distinguish  it  from  ordinary 
powdered  iron,  and  it  may  likewise  be  considered  a  test  for  its 
entire  reduction,  if  it  ignites  readily  and  burns  rapidly,  until 
the  whole  mass  is  converted  to  the  oxide  of  a  uniform  reddish 
brown  color.  But  even  this  behaviour  will  not  prove  its  abso- 
lute purity,  as  will  be  shown  below. 
A  sample  of  reduced  iron  of  a  rather  black  color  induced  me 
to  procure  various  samples  of  this  preparation,  none  of  which 
were  entirely  soluble  in  diluted  hydrochloric  acid,  some  even  re- 
quiring prolonged  digestion  in  nitromuriatic  acid  ;  but  all  ignited 
by  a  match  more  or  less  readily,  and  burned  partly  or  wholly  to 
products  from  a  brownish  black  to  a  reddish  brown  color.  Of  the 
eight  samples  which  I  thus  examined,  the  origin  of  three  could 
be  ascertained,  and  I  concluded  to  ascertain  their  purity  by 
analysis.  They  were  all  free  from  lead,  copper,  zinc  and 
similar  metals. 
No.  1  was  of  American  manufacture,  possessed  a  rather  black 
color,  which  appeared  brownish  gray  when  a  small  quantitv 
was  rubbed  upon  white  paper  ;  it  ignited  with  some  difficulty 
by  a  lighted  match,  and  burned  slowly  and  incompletely, 
yielding  a  product,  a  portion  of  which  had  a  reddish  black 
color,  while  the  remainder  was  apparently  unaltered  and  could 
not  be  ignited.  It  dissolved  partly  in  cold  and  heated  muria- 
tic and  nitric  acid^  entirely  in  cold  nitromuriatic  acid  by  pro- 
longed contact,  but  instantly  when  heated ;  another  portion 
from  the  same  bottle,  however,  dissolved  with  less  facility  in 
