Am.  Jour,  Pharm, "( 
March,  1885.  j 
Tincture  of  Fe^^ric  Chloride. 
119 
removed  by  heat,  sufficient  distilled  water  to  make  the  whole  produc- 
weigh  100  parts  (25  oz.  av.). 
The  ^'Tincture''  may  be  made,  if  so  desired,  by  the  simple  admix- 
ture of  this  new  liquor  with  alcohol  in  the  proportion  of  35  parts  to 
65  parts,  as  of  old,  and  mixing  the  liquids ;  no  previous  standing 
before  medicinal  employment  being  necessary.  But  concerning  the 
tincture,  more  especially  the  officinal  one,  there  are  quite  a  number  of 
views  held  regarding  its  utility  and  value  over  a  liquor  of  similar 
strength,  as  questionable.  The  National  Dispensatory,"  p.  901,  in 
speaking  of  the  liquor  (U.  S.  P.,  1880),  says  of  it,  that  It  is  not 
altered  by  exposure  to  sunlight,  except  in  the  presence  of  various 
organic  matters,  by  which  the  salt  is  partially  reduced  to  ferrous  chloride  " 
and  again,  the  same  authority,  under  the  tincture  (U.  S.  P.,  J  880),  p. 
1526,  says,  that  ^'  Notwithstanding  this  gradual  reduction  (in  the  tinc- 
ture) is  well  known,  the  U.  S.  P.  requires  the  tincture  on  the  addition 
of  freshly  prepared  solution  of  potassium  ferricyanide,  to  acquire 
merely  a  greenish-brown  color,  without  a  trace  of  blue,  which  is 
simply  an  impossibility."  In  further  corroboration  of  the  reducing 
action  of  alcohol  and  sunlight  combined  on  ferric  chloride  solution, 
when  prepared  by  the  officinal  method.  Professor  Attfield,  in  the  last 
edition  of  his  Chemistry,"  p.  146,  in  commenting  upon  the  tincture 
(U.  S.  P.,  1880),  remarks,  that  "The  spirit  in  the  tincture  is  unneces- 
sary, useless  and  deleterious ;  for  it  acts  neither  as  a  special  solvent 
nor  as  a  preservative,  the  offices  usually  performed  by  alcohol  and 
unless  the  liquid  contains  excess  of  acid,  decomposes  the  ferric  chloride 
and  causes  the  formation  of  an  insoluble  oxychloride  of  iron.  Even  if 
the  tincture  be  acid  it  slowly  loses  color ;  ferrous  chloride  and  chlori- 
nated etherial  bodies  being  formed.  A  liquor  of  similar  strength  is 
doubtless  destined  to  displace  the  tincture  altogether."  Further 
evidence  in  conformation  of  these  view\s,  is  given  by  Mr.  R.  Pother  in 
his  paper  on  "  Ferric  Chlorides "  ^  to  which  previous  reference  has 
been  made,  when  he  says,  that  In  regard  to  the  officinal  proportion 
of  alcohol  in  the  tincture,  it  may  be  said  that  it  is  unnecessarily  great. 
Whilst  a  moderate  amount,  say  35  per  cent.,  may  be  beneficial,  any 
large  excess  may  be  fairly  judged  as  a  species  of  impurity,  aside  from 
being  a  positive  waste."  Now  the  evidence  adduced  from  these  ex- 
tracts and  also  from  the  remarks  previously  made  is,  that  the  prepara- 
1  "American  Journal  of  Pharmacy,"  August,  1884,  p.  409. 
