312 
Crystallized  Digitalin, 
{  Am.  Jour.  Pharm. 
t     July,  1875. 
EXTRACTION  OF  CRYSTALLIZED  DIGITALIN. 
BY   C.   A.  NATIVELLE. 
Leaves  of  digitalis  should  be  gathered  from  two-year  old  plants  when 
beginning  to  flower,  the  stalks  and  midribs  being  discarded,  as  these 
parts  contain  very  little  digitalin.  For  analysis  100  grams  may  be  used, 
but  with  care  20  grams  will  be  sufficient.  On  a  larger  scale  the  follow- 
ing is  the  method  employed  : — 1,000  grams  of  the  leaves  are  reduced 
to  a  fine  powder  and  added  to  250  grams  of  neutral  lead  acetate  dis- 
solved in  1,000  grams  of  distilled  water.  The  mixture  is  passed  through 
a  sieve  and  allowed  to  stand  for  24  hours  with  occasional  stirring.  It 
is  then  allowed  to  settle  and  the  subsided  mass  exhausted  with  alcohol 
of  50°  until  all  bitterness  ceases.  To  this  liquid  a  saturated  solution 
of  40  grams  of  sodium  bicarbonate  in  cold  water  is  added  ;  and  after 
the  effervescence  has  ceased,  the  alcohol  is  distilled  off,  the  residue 
evaporated  in  the  water-bath  to  2,000  grams,  and  then  diluted  with  its 
own  weight  of  water.  Two  or  three  days  afterwards  the  clear  liquid 
is  siphoned  off,  and  the  precipitate  passed  through  a  linen  strainer  and 
pressed.  The  precipitate  is  suspended  in  1,000  grams  of  alcohol  of 
80°  and  strained  through  a  metallic  or  fine  linen  sieve  ;  the  turbid  liquid 
is  raised  to  ebullition,  and  a  solution  of  10  grams  of  neutral  lead  acetate 
added  ;  the  ebullition  is  continued  for  some  minutes  and  the  liquid  then 
cooled  and  filtered,  the  percipitate  being  thrown  on  the  filter  and 
squeezed  ;  50  grams  of  finely-powdered  vegetable  carbon,  washed  with 
acid  and  quite  neutral,  are  then  added  ;  the  alcohol  is  distilled  off ;  and 
the  residue,  after  being  heated  for  some  time  in  the  water-bath  to  drive 
off  the  last  traces  of  alcohol,  is  strained  through  a  sieve.  The  carbon 
residue  is  dried  and  exhausted  by  displacement  with  pure  chloroform 
until  the  washings  are  colorless,  and  the  liquor  is  distilled  and  evapora- 
ted to  dryness.  The  residue  is  crude  digitalin  mixed  with  pitchy  mat- 
ter and  oil.  It  is  dissolved,  with  gentle  heat,  in  100  grams  alcohol  of 
90°,  I  gram  of  neutral  lead  acetate  dissolved  in  a  little  water  is  added, 
together  with  10  grams  of  washed  animal  charcoal  in  fine  grains,  with- 
out powder;  the  mixture  is  boiled  for  10  minutes  and  cooled,  then  al- 
lowed to  settle,  and  filtered  through  cotton  wool,  the  carbon  deposit 
being  last  thrown  on  the  filter  ;  this  deposit  is  exhausted  with  alcohol, 
and  the  alcohol  is  distilled  off,  whereupon,  the  digitalin  is  left  as  a  clot- 
ted, crystalline  mass,  contaminated  only  by  colored  oil.  To  obtain  a 
white  product,  the  mass  is  dissolved  by  heat  in  8  grams  of  alcohol  of 
