362 
Infusion  of  Digitalis. 
<  Am.  Jour.  Pharm. 
\       July.  1892. 
which  the  best  results  are  obtained.  The  so-called  active  principles 
of  digitalis  are  very  numerous,  and  it  is  now  accepted  that  many  of 
them  are  decomposition  products — products  which  have  been  the 
result  of  decomposition  of  the  truly  active  principles  in  the  plant 
during  plant-life,  by  the  plant  acids  and  saline  compounds,  as  claimed 
by  Kosmann,  and  products  which  have  been  the  result  of  decompo- 
sition by  reagents,  during  plant  exhaustion  and  after  treatment  of 
extract.    The  results  of  the  later  analyses  all  show  this. 
The  name  digitalin  has  been  given  to  a  number  of  products, 
but  is  now  generally  reserved  for  the  compound  obtained  by 
Schmiedeberg  (1874),  with  which  Kosmann's  insoluble  digitalin  is 
supposed  to  be  identical.  It  has  also  been  established  that  the  other 
digitalins,  whether  crystallized  or  amorphous,  are  varying  mixtures 
of  Schmiedeberg's  digitalin,  digitoxin,  digitonin,  digitalein,  and 
decomposition  products.  Of  these  compounds,  all,  save  digitoxin, 
are  glucosides.  Including  the  decomposition  products,  they  may 
be  grouped  .in  two  classes,  according  to  solubility.  First,  those 
soluble  in  alcohol  and  insoluble  or  almost  insoluble  in  water  ;  second, 
those  soluble  in  both  alcohol  and  water.  Digitoxin  and  digitalin 
belong  to  the  first  group,  and  digitonin  and  digitalein  belong  to  the 
second  group.  Hence,  it  will  be  seen,  that  the  tincture  and  fluid 
extract  contain,  most  largely,  digitoxin  and  digitalin,  with  some 
digitonin  and  digitalein,  whilst  the  infusion  contains  digitonin  and 
digitalein,  with  no  digitoxin  or  digitalin.  This  explains  the  differ- 
ence in  therapeutical  action  between  the  two  preparations. 
In  the  paper  on  infusion  of  digitalis,  previously  referred  to,  it  was 
shown  tnat  cold-water  maceration  was  preferable  to  hot-water 
maceration,  in  that  less  coloring  matter  and  more  of  the  Colorless 
active  principles  were  dissolved  ;  that  the  toxicity  of  digitalis  very 
notably  diminished  when  the  product  of  maceration  was  concen- 
trated by  a  water-bath ;  that  the  English  leaves  were  superior  to 
the  German  only  because  the  commercial  samples  of  the  former  were 
carefully  selected  and  freed  from  the  stalks,  thereby  reducing  the  ele- 
ment of  variability  to  a  minimum  ;  that  the  use  of  cinnamon  in  the 
official  infusion  was  objectionable  because  its  presence  exerted  a  retard- 
ing influence  upon  the  solution  of  the  water-soluble  principles,  and 
that,  for  the  usual  quantities  of  infusion  made,  one  hour's  maceration, 
with  occasional  agitation,  was  all  sufficient.  A  formula  for  making 
the  infusion  was  presented. 
