Am.  Jour.  Pharm. 
Aug.,  1892. 
Digit  aim. 
421 
hours  crystals  were  formed  abundantly  (A) ;  these  were  separated 
by  a  suction  pump,  and  when  washed  with  a  few  drops  of  water 
were  nearly  colorless.  The  mother  liquor  was  diluted  and  boiled 
with  barium  carbonate,  the  filrate  carefully  saturated  with  alcohol, 
and  left  for  some  time  in  a  closed  flask,  the  sides  of  which  were 
frequently  rubbed.  After  some  days  warty  crystals  (B)  were  formed, 
which  were  separated  from  the  mother  liquor  by  washing  with  50 
per  cent,  alcohol  and  pressing.  After  separating  the  barium  from 
the  mother  liquor  by  sulphuric  acid  and  evaporating,  a  second 
crystallization  of  the  substance  A  was  obtained,  and  when  the 
mother  liquor  from  it  was  again  converted  into  barium  salt  as 
before,  a  further  quantity  of  the  substance  B  was  obtained.  By  this 
somewhat  troublesome  but  certain  method  it  was  possible  to  sepa- 
rate the  two  acids  produced  by  the  action  of  bromine. 
On  recrystallizing  the  substance  A,  it  was  obtained  in  fine  color- 
less crystals,  readily  soluble  in  water  or  alcohol,  sparingly  in  ether ; 
the  crystals  had  a  neutral  reaction,  and  consisted  of  the  lactone  of  a 
new  acid,  digitalonic  acid.  The  air  dry  substance  does  not  lose 
water  in  a  vacuum  over  sulphuric  acid;  a  little  above  1300  C.  it 
begins  to  aggregate,  and  it  melts  at  138-1390  C.  Analysis  gave 
results  leading  to  the  formula  C.H1205.  On  heating  with  potash  or 
soda  solution,  salts  of  the  acid  are  obtained  which  do  not  crystallize. 
Moderately  dilute  solutions  of  these  salts  mixed  with  silver  nitrate 
give  in  a  short  time  an  abundant  deposit  of  silver  digitalonate  in 
microscopic  needles,  C7H1306Ag.  When  this  salt  is  heated  a  pro- 
duct sublimes  in  fine  needles. 
From  what  has  been  stated  it  would  appear  that  in  the  splitting 
up  of  digitalin  the  sugar  produced,  digitalose,1  which  has  the  com- 
position C7HuOs,  and  according  to  its  behavior  with  bromine,  it 
contains  an  aldehydradicle.  In  its  composition  it  is  closely  related  to 
rhamnose,  and  for  that  reason  it  ought  to  possess  a  great  capability 
of  crystallizing.  Further  investigation  must  determine  what  may  be 
the  explanation  of  the  contrary  character  which  has  been  described. 
The  barium  salt  B  obtained  from  the  mother  liquor  of  the  lactone 
was  also  readily  purified  by  recrystallization  ;  it  then  formed  sharply 
defined  laminae  having  the  appearance  and  composition  of  barium 
1  This  name  has  been  applied  by  Homolle  and  Ouevenne  {Mem.  sur  la 
digitaline)  not  to  a  chemically  individual  substance,  but  to  a  mixture  of 
glucosides  and  their  product  of  decomposition. 
