4o  Churchill's  Tincture  of  Iodine.      {^fig  ^S"" 
page  278,  of  the  Proceedings  of  the  American  Pharmaceutical  As- 
sociation in  1886: 
Iodine   75  grains. 
Potassium  iodide   15  grains. 
Water    2  drachms. 
Alcohol   6  drachms. 
Churchill's  original  formula  called  for  75  per  cent,  alcohol,  but  by 
mixing  the  U.  S.  P.  alcohol  and  water  in  the  proportion  given  a  75 
per  cent,  alcohol  will  be  closely  approximated. 
Before  going  further  it  might  be  best  to  mention  that  this  tinc- 
ture should  not  be  confused  with  liquor  iodi  causticus,  or  Churchill's 
iodine,  the  formula  for  which  is  published  on  page  248,  Volume  34, 
Proceedings  American  Pharmaceutical  Association,  and  consists  of: 
Iodine    120  grains. 
Potassium  iodide   240  grains. 
Water    1  ounce. 
It  contains  twice  as  much  iodide  as  iodine  and  is  much  stronger  in 
iodine  content.  This  preparation  was  official  in  X.  F.  I,  II,  III, 
but  not  any  more  in  X.  F.  IV. 
The  following  formula  for  Churchill's  tincture  of  iodine  was 
published  in  1888  in  the  first  edition  of  the  X'ational  Formulary  of 
Unofficial  Preparations : 
Iodine    2T/2  Troy  ounces. 
Potassium  iodide   J/2  Troy  ounce. 
Water    4     fluid  ounces. 
Alcohol,  to  make   16     fluid  ounces. 
The  National  Formulary  II  and  III  give  the  following  formula 
for  Churchill's  tincture  of  iodine  under  the  title  Tinctura  Iodi, 
Churchill : 
Iodine   165  Gm. 
Potassium  iodide    33  Gm. 
Water    250  Cc. 
Alcohol,  to  make    1,000  Cc. 
The  same  formula  is  official  in  X.  F.  IV,  191 6.  under  the  title  of 
Tinctura  Iodi  Fortior,  stronger  tincture  of  iodine,  with  the  synonyms 
Tinctura  Iodi,  Churchill ;  Churchill's  tincture  of  iodine. 
