TINCTURA  lODINII  DECOLORATA. 
345 
introduce  glycerin  into  the  menstrua  for  some  fluid  extracts, 
especially  for  those  that  are  prepared  from  astringent  drugs. 
If  by  the  above  remarks  I  have  succeeded  in  interesting  any  of 
the  numerous  pharmacists  of  our  country,  I  trust  that  they  will 
find  pleasure  in  experimenting  upon  a  subject  which,  although 
so  far  mainly  theory,  I  hope  soon  to  be  enabled  to  present  in  a 
more  practical  shape, 
Louisville,  February,  1869. 
—  The  Pharmacist,  Chicago,  March,  1869. 
TINCTURA  lODINII  DECOLORATA. 
By  Chas.  0.  CuRTMAN,  M.  D., 
Prof,  of  Chemistry  in  the  Missouri  Medical  College. 
A  colorless  tincture  of  iodine  for  external  application  to  the 
face,  neck  and  hands,  has  so  many  obvious  advantages  over  the 
common  officinal  compounds  that  various  efforts  have  been 
made  to  obtain  a  reliable  preparation,  which,  while  it  retains 
the  valuable  properties  of  the  iodine,  does  away  with  its  objec- 
tionable features.  Most  prominent  among  these  objections  are 
the  unsightly  stains  inseparable  from  the  use  of  the  common 
tinctures.  Different  formulae  have  been  from  time  to  time  made 
public  for  accomplishing  decoloration ;  some  of  them  using 
alkaline  sulphites,  or  hyposulphites,  which  convert  the  free 
iodine  into  an  alkaline  iodide,  and  have  no  preference  over  •  a 
simple  solution  of  iodide  of  potassium  or  sodium.  Others  effect 
the  discharge  of  the  color  by  carbolic  acid,  which  certainly 
gives  good  results,  but  may  not  always  be  considered  a  desira- 
ble addition ;  others  again  convert  the  free  iodine  of  either  the 
simple  or  compound  tincture  into  ammonia  compounds  by  the 
addition  of  aqua  ammonige  in  various  proportions,  and  this  seems 
to  me  the  method  deserving  preference  over  the  others  on  ac- 
count of  the  greater  volatility  of  the  resulting  product,  and  its 
better  adaptation  to  speedy  absorption.  The  formulae  based 
upon  the  action  of  ammonia,  however,  differ  widely  in  their 
proportions  of  iodine  and  of  ammonia  among  themselves,  and 
from  the  corresponding  officinal  preparations  of  the  U.  S.  Phar- 
macopoeia, and  varying  so  much  in  strength  they  have,  perhaps 
on  that  account,  found  less  favor  than  they  deserve. 
