Am.  Jour.  Pharm.\ 
March,  1900.  j 
Soluble  Ferric  Pyrophosphate. 
125 
All  of  these  adulterations  belong  to  the  compositse,  two  being 
cultivated  varieties  of  chrysanthemum,  and  hence  those  most  liable 
to  be  used  by  the  dealer  in  trying  to  imitate  the  true  drug  by  color- 
ing matter  and  other  available  means. 
Yellow  chrysanthemum  :  Petal,  30  x  7  millimetres;  pollen  grains, 
42-84  mikrons  in  diameter,  with  adhering  oil  globules  ;  wall,  1785 
mikrons;  spines,  1785  mikrons,  and  chromoplastids,  2*677  mikrons. 
Scarlet  chrysanthemums:  Petal,  32  x  5  millimetres  ;  pollen  grains, 
absent,  and  chromoplastids,  2-677  mikrons. 
Sunflower:  Petals,  40  x  10  millimetres;  pollen  grains,  32-13 
mikrons  in  diameter ;  wall,  2  677  mikrons;  spines,  4-462  mikrons, 
and  chromoplastids,  3-57  to  4-462  mikrons. 
SOLUBLE  FERRIC  PYROPHOSPHATE. 
By  W.  E.  Ridenour. 
Research  Committee  E,  Pharmacopoeia  Revision. 
The  investigation  herein  presented  was  suggested  by  the  state- 
ment of  a  very  large  pharmaceutical  manufacturing  firm,  that  no 
"Iron  Pyrophosphate,  Soluble,"  on  the  market  would  answer  the 
U.S  P.  requirements,  especially  in  regard  to  the  absence  of  ortho- 
phosphate. 
A  fewT  years  ago  Dr.  Julius  Stieglitz1  gave  a  very  exhaustive  paper 
on  a  method  for  distinguishing  orthophosphoric  acid  fro.m  pyro- 
phosphoric  acid  by  the  use  of  magnesium  sulphate  and  acetic  acid 
In  this  connection  the  author  mentioned  that  the  soluble  pyrophos- 
phate of  iron  as  found  on  the  market  varied  to  a  marked  degree, 
some  of  the  samples  examined  containing  only  a  trace  of  orthophos- 
phate,  while  others  showed  the  absence  of  any  pyrophosphate;  and 
in  view  of  these  results,  asked  the  interesting  question  as  to  whether 
soluble  pyrophosphate  of  iron  reverts  during  the  process  of  manu- 
facture. 
In  1892  F.  A.  Thompson2  reported  the  examination  of  several 
samples  of  soluble  pyrophosphate  of  iron  according  to  the  directions 
of  the  U.S. P.,  with  the  result  that  all  contained  orthophosphate. 
J.  B.  Naglevoort3  favored  Fresenius'  method  for  the  detection  of 
1  Am.  Jocr.  Pharm.,  1891,  585-593. 
2  Proc.  Am.  Ph.  Assoc.,  1892,  259. 
3Am.  Jour.  Pharm.,  1895,  210. 
