316 
CRYSTALLIZED  DIGITALIN. 
of  the  distillation  holds  in  suspension  numerous  little  crystals 
mixed  with  a  sticky  yellowish  paatter  strongly  bitter.  The 
crystals  are  not  digitalin,  which  last  is  in  the  yellow  matter. 
This  is  evaporated  in  a  water-bath  till  reduced  to  about  10  parts. 
Separate  this  matter  from  the  dense  liquid,  wash  it  with  a  little 
cold  water  and  spread  it  on  porous  papers  to  dry.  Two  or 
three  parts  of  this  substance  are  obtained,  which  is  dissolved 
hot  in  a  flask  with  double  its  weight  of  alcohol  and  set  aside  in 
a  cool  place.  The  inert  crystalline  substance  is  deposited  first, 
and  after  some  days  yellowish  radiating  crystals  of  digitalin 
appear  among  them.  When  the  latter  cease  to  increase  put  the 
whole  on  a  funnel  closed  with  cotton,  allow  the  mother  water  to 
drain,  and  then  wash  them  with  alcohol  of  15  per  cent.  The 
crystalline  residue  is  then  dissolved  in  boiling  alcohol  of  80  per 
cent.,  boiled  with  a  little  animal  charcoal,  filtered,  concentrated 
to  one-half  and  allowed  to  become  a  crystalline  mass  on  cool- 
ing. After  several  days  separate  the  mother  water,  dry  the 
crystals,  powder  them  and  put  them  in  a  flask  with  20  parts  of 
pure  chloroform  and  agitate  well.  The  digitalin  only  is  dis- 
solved, and  is  obtained  by  distillation  to  regain  the  chloroform. 
The  digitalin  in  this  state  has  a  yellowish  color,  to  remove  which 
and  get  it  white  it  is  necessary  to  dissolve  it  in  boiling  alcohol, 
agitate  with  a  little  carefully  prepared  animal  charcoal,  filter 
and  crystallize.  1000  parts  of  digitalis,  after  it  has  been  ex- 
hausted by  water,  yields  one  part  of  pure  crystallized  digitalin. 
Properties  and  analysis.  Thus  obtained  digitalin  is  neutral, 
odorless,  intensely  and  persistently  bitter  like  digitalis,  and 
contains  no  nitrogen.  Its  insolubility  in  water  causes  its  taste 
to  be  slowly  developed  unless  aided  by  alcohol.  It  is  very 
soluble  in  chloroform ;  in  12  parts  of  alcohol  of  90  per  cent,  and 
in  6  parts  boiling ;  less  soluble  in  anhydrous  alcohol  ;  ether  free 
from  alcohol  dissolves  but  a  trace.  Even  boiling  water  dissolves 
very  little  yet  acquires  a  decided  bitterness. 
Sulphuric  acid  dissolves  it  with  a  greenish  tint  which  becomes 
reddish  by  bromine  vapor. 
Nitric  acid  dissolves  it  without  color  at  first,  but  afterwards 
is  yellowish. 
Muriatic  acid  dissolves  it  with  a  greenish  yellow  color  passing 
