( 
Am7u0iy"i899arm-}      Tincture  of  Fat-Free  Digitalis.  335 
After  the  benzin  treatment  the  dried  and  powdered  leaves  are 
made  into  a  tincture  according  to  the  process  for  the  official  pro- 
duct, 150  grammes  of  leaves  being  used  to  make  1,000  c.c,  with 
diluted  alcohol,  with  this  difference,  that  the  receiver  is  removed 
when  the  total'  percolate  amounts  to  about  980  c.c ,  and  it  is  then 
carefully  neutralized  with  a  sufficient  quantity  (about  10  or  15  c.c.)  of 
the  official  10  per  cent,  ammonia  water,  and  the  product  is  made  to 
measure  1,000  c.c.  with  sufficient  fresh  percolate  or  diluted 
alcohol. 
Or,  with  the  usual  weights  and  measures,  1,094  grains  of  the 
powdered  leaves  may  be  exhausted  with  diluted  alcohol  to  yield 
151^  fluidounces,  and  then  about  1  or  2  fluiddrachms  of  10  per  cent, 
ammonia  water  will  be  required  to  effect  neutralization,  after  which 
sufficient  percolate,  or  diluted  alcohol,  should  be  added  to  make  the 
whole  product  measure  1  pint.  After  standing  for  twenty-four 
hours  the  freshly-made  tincture  usually  precipitates  some  coloring 
matters,  etc.,  which  should  be  removed  by  filtration  through 
paper. 
The  product,  as  finally  obtained,  is  a  deep  reddish  brown,  almost 
black  liquid,  keeping  perfectly  for  years,  of  not  unpleasant  odor, 
and  pure  bitter  taste.  It  has  not  the  acrid  odor  or  taste  of  the  official 
tincture,  and,  unlike  the  latter,  does  not  become  turbid  on  admixture 
with  water,  but  remains  transparent  with  any  amount  of  dilution. 
The  purposes  of  this  procedure  are  two-fold :  First,  the 
benzin  treatment  removes  the  fat,  and  probably  all  the  nauseating 
and  odorous  principles,  and  secondly,  the  ammonia  treatment 
neutralizes  the  free  acids  present  in  the  leaf,  forming  ammonium 
salts. 
It  does  more  than  this.  The  neutralization  with  ammonia  makes 
all  the  proximate  principles  in  the  tincture  water-soluble,  and  not 
partly  so  as  in  the  official  product.  (When  the  official  tincture  is 
diluted  with  water  it  precipitates.)  This  is  especially  valuable  for  the 
reason  that  all  compounds  before  absorption  by  tissues  must  first 
be  made  soluble  before  they  can  be  absorbed.  By  this  means  absorp- 
tion is  facilitated  and  assimilation  is  hastened,  as  will  be  shown  by 
pharmacological  results  later. 
When  the  fat-free  tincture  was  first  made,  the  desire  was  to  ob- 
tain a  preparation  that  would  not  nauseate,  and  clinical  results  in 
the  Philadelphia  Hospital  have  shown  that  this  object  has  been  very 
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