ON  TINCTURA  FERRI  CHLORIDI. 
17 
ON  TINCTURxl  FERRI  CHLORIDI. 
Read  at  the  Pharmaceutical  Meeting  of  the  Philadelphia  College  of 
Pharmacy,  held  Dec.  3d,  1861. 
By  W.  H.  Pile,  M.  D.,  Philadelphia. 
Every  practical  druggist  must  be  aware  of  the  uncertainty  and 
perplexity  attending  the  preparing  of  muriated  tincture  of  iron, 
the  more  annoying  as  this  arises  not  from  any  want  of  skill  on 
his  part.  In  fact,  it  is  almost  impossible  to  predict  the  result 
of  his  labors,  and  the  conscientious  druggist  has  often  the  mor- 
tification of  finding  his  best  endeavors  unavailing  in  obtaining  a 
satisfactory  preparation,  and  his  time  and  materials  together 
thrown  away.  Numerous  methods  have  been  suggested  and 
devised  to  overcome  these  difficulties,  as  may  be  seen  by  glanc- 
ing back  over  the  various  Pharmaceutical  Journals  of  our  own 
and  foreign  countries,  some  of  these  no  doubt  would  yield  good 
results,  yet  in  general  they  are  not  practical  enough  for  out 
Pharmaceutists,  requiring  apparatus  which  the  generality  of 
druggists  would  rather  dispense  with. 
The  object  of  this  paper  is  to  suggest  a  modus  operandi,  by 
which  a  uniform  preparation  may  be  secured,  independent  of 
those  variations  of  materials,  which  are  unfortunately  so  often 
met  with. 
These  variations  are  with  respect  to  the  muriatic  acid,  it 
being  either  too  strong,  or  which  is  more  usually  the  case,  defi- 
cient in  that  particular. 
As  regards  the  precipitated  carbonate  of  iron  a  greater  diffi- 
culty exists,  even  when  pure ;  that  is,  when  containing  no  adul- 
teration. The  solubility  in  acid,  of  different  samples,  is  ex- 
ceedingly various,  some  specimens  being  almost  entirely  insolu- 
ble, while  in  the  greater  number,  the  digestion  and  heating  calls 
for  the  greatest  exercise  of  patience. 
This  difference  of  solubility  appears  to  arise  from  some  pe- 
culiar state  of  aggregation,  and  likewise,  according  to  Gmelin, 
from  its  state  of  hydration  or  combination  with  water. 
These  varying  conditions  are  no  doubt  caused  by  precipita- 
ting, washing  and  drying  at  different  temperatures,  or  a  too  pro- 
longed exposure  to  the  air. 
I  have  never  yet  met  with  a  sample,  however  pure,  that  would 
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