420  Digitalin.  {Am-iug!;Sarm- 
least  possible  proportion  of  93  per  cent,  alcohol,  digitaligenin  may 
be  obtained  in  colorless  crystals. 
Digitaligenin  is  insoluble  in  water,  sparingly  soluble  in  ether  free 
from  alcohol,  and  readily  soluble  in  alcohol,  especially  on  heating. 
It  dissolves  in  sulphuric  acid  or  ordinary  oil  of  vitriol  with  the 
same  coloration  as  digitalin.  The  dry  crystals  of  the  pure  substance 
become  highly  electric  when  rubbed.  They  melt  at  210-212°. 
Analysis  gave  results  leading  to  the  formula  C16H2202,  and  from  the 
composition  of  several  derivatives  it  appears  very  probable  that 
this  is  a  correct  formula. 
Professor  Boehm  informs  me  that  when  applied  to  frogs,  digita- 
ligenin has  no  action.  For  the  purpose  of  identifying  the  remain- 
ing products  of  the  transformation,  the  watery  liquid  which  had 
been  extracted  with  ether  was  again  shaken  with  chloroform  to 
remove  a  small  .quantity  of  resinous  substance,  then  warmed  to 
drive  off  chloroform  and  ether,  and  after  cooling  treated  with  silver 
oxide  to  separate  hydrochloric  acid.  The  liquid  was  then  evapor- 
ated to  a  syrupy  consistence,  and  left  for  some  months  to  crystallize, 
partly  alone  and  partly  with  addition  of  suitable  solvents ;  but  up 
to  the  present  there  have  been  no  signs  of  crystallization,  a  circum- 
stance which  seems  very  remarkable  when  the  further  results  of  the 
investigation  are  considered. 
An  attempt  was  then  made  to  obtain  a  knowledge  of  the  nature 
of  the  sugar  by  preparing  an  osazone.  Without  much  difficulty  a 
product  was  obtained  which  crystallized  very  well,  and  was  appar- 
ently an  individual  osazone  melting  at  2060  C;  but  the  analysis  of 
this  substance  obtained  in  different  operations  gave  results  which 
were  but  little  in  accord,  and  did  not  correspond  with  any  known 
member  of  the  class  of  compounds.  Consequently,  the  presence  of 
a  mixture  of  sugars  was  to  be  suspected,  and  for  their  examination 
the  method  of  oxidation  by  means  of  bromine  proved  very  service- 
able. From  one  of  the  two  acids  produced  a  lactone  was  obtained 
which  crystallized  well,  and  from  the  other  a  readily  crystallizable 
barium  salt 
The  thick  syrup  was  mixed  with  2  parts  of  bromine  after  dilution 
with  5  parts  of  water,  and  by  means  of  constant  shaking  the 
bromine  was  absorbed  rapidly.  After  driving  off  the  dissolved 
bromine  and  removing  the  hydrobromic  acid  by  silver  oxide, 
the  liquid  was  evaporated  to  a  syrupy  consistence.    Within  some 
