244 
Assay  of  Iron  Filings. 
Am.  Jour.  Pharm. 
April,  1920. 
ether,  and  carbon  tetrachloride,  while  it  remained  insoluble  in  al- 
cohol. 
The  following  is  a  record  of  observations  made  on  heating  the 
fat  slowly  from  15°  C.  to  240°  C: 
15°  0.-50°  C. — The  fat  became  less  granular,  finally  assuming 
a  homogeneous  appearance,  and  was  of  a 
dark  brown  color. 
50°  C.-ioo°  C. — No  change  observed,  except  that  the  other  color 
assumed  a  redder  tint. 
100°  C.-iio°  C. — More  transparent. 
120°  C.-i3o°  C— Color  still  lighter. 
130°  C.-i8o°  C. — Appearance  of  small  bubbles,  probably  due 
to  the  escape  of  a  small  quantity  of  volatile 
matter. 
200°  0.-240°  O. — A  greenish  brown  mobile  liquid. 
On  cooling,  the  fat  remained  as  a  brown  viscous  liquid  of  the 
consistency  of  castor  oil,  and  the  solubility  remained  as  that  of  the 
original  fat.  On  exposure  in  thin  layers  this  liquid  did  not  exhibit 
the  character  previously  recorded  of  the  fat.  During  two  days  no 
film  appeared,  whereas  on  further  exposure  the  thinnest  portions 
formed  a  transparent  skin  of  the  nature  of  a  varnish. 
In  conclusion,  the  evidence  is  that  the  fat  shows  certain  char- 
acteristics of  drying  oils,  such  as  Tung  oil,  without  the  property  of 
producing  a  varnish,  as  is  the  case  with  drying  oils,  such  as  Linseed 
oil,  whereas  after  heating  it  behaves  as  a  semi-drying  oil,  and  it 
would  seem  that  in  this  condition,  admixed  with  drying  oils,  it 
might  be  used  in  the  production  of  paints  and  varnishes. 
THE  ASSAY  OF  IRON  FILINGS  FOR  PHARMAOEUTIOAL 
USB.* 
By  H.  H1NDI.EY,  Ph.  C. 
Iron  in  the  form  of  fine  filings,  though  not  official  in  the  B.  P., 
is  frequently  used  in  the  manufacture  of  medicinal  preparations 
containing  iron,  instead  of  nails  or  wire,  and  as  it  is  more  liable  to 
contamination  in  this  form,  it  demands  more  careful  examination. 
From  a  medicinal  point  of  view  its  actual  content  of  metallic  iron 
*  From  The  Pharm.  Jour,  and  Pharm.,  Feb.  7,  1920. 
