Am.  Jour.  Pharru. 
Sept.,  1891. 
Digit onin  and  Digitogenin. 
455 
digitogenin  does  not  agree  with  the  production  of  two  sugars  from 
digitonin,  which  latter  fact  points  to  the  existence  of  two  hydroxyl 
groups  in  digitogenin. 
Digitogenin  on  oxidation  yields,  according  to  the  conditions,  three 
acids,  which  the  author  names  respectively  digitogenic,  oxydigi- 
togenic  and  digitic  acids. 
Digitogenic  Acid,  CuH2204,  is  prepared  by  slowly  adding  chromic 
acid  (o*7  part  dissolved  in  1-4  parts  of  water  and  7  parts  of  acetic 
acid]  to  a  solution  of  digitogenin  (1  part)  in  acetic  acid  (30  parts). 
As  soon  as  all  the  chromic  acid  is  reduced,  an  equal  volume  of  water 
is  added,  and  the  mixture  repeatedly  extracted  with  ether.  The 
ethereal  solution  is  allowed  to  remain  for  24  hours,  poured  off  from 
the  deposit  which  is  formed,  the  ether  distilled  off,  and  the  acid 
residue  evaporated  on  the  water-bath  until  a  crystalline  crust  forms 
on  the  liquid;  the  product  crystallizes  after  12  hours.  The  yield 
amounts  to  60  per  cent,  of  the  digitogenin  employed.  It  crystal- 
lizes from  absolute  alcohol  in  colorless  needles  or  thin  prisms,  begins 
to  melt  at  1460,  and  is  completely  melted  at  1500,  becomes  strongly 
electric  when  rubbed,  tastes  extremely  bitter,  and  is  "easily  soluble 
in  chloroform  and  hot  glacial  acetic  acid,  less  easily  in  50  per  cent, 
acetic  acid,  more  sparingly  in  cold  alcohol  and  ether,  and  insoluble 
in  water ;  when  heated  with  water,  it  melts.  When  moistened  with 
dilute  alcohol,  it  has  a  distinctly  acid  reaction.  It  dissolves  easily 
in  alkali  hydroxides  and  carbonates.  The  magnesium  salt  (CUH21- 
04)2Mg,  prepared  by  adding,  an  excess  of  dilute  magnesium  nitrate 
(1  :  10)  to  a  very  dilute  neutral  solution  of  the  acid,  separates  as  a 
crust  consisting  of  aggregates  of  minute  needles  on  allowing  the 
mixture  to  remain  for  24  hours.  The  calcium  salt  is  similar  to  the 
magnesium  salt.  The  bye-products  of  the  oxidation  with  chromic 
acid  probably  contain  formaldehyde  or  formic  acid,  as  no  evolution 
of  carbonic  anhydride  was  observed.  The  mother  liquors  contained 
a  small  quantity  of  an  aldehydic  or  ketonic  compound  and  a  large 
quantity  of  an  acid  of  high  molecular  weight  which  yields  no  crys- 
talline derivatives. 
Oxy digitogenic  acid,  2CuH20O4  -f-  H20,  is  prepared  by  dissolving 
digitogenic  acid  (1  part)  in  potash  (1  :  10)  (10  parts),  diluting  the 
solution  to  100  parts,  and  adding  a  solution  of  potassium  permar 
ganate  (1  :  50).    When  the  oxidation  is  finished,  the  solution  is 
decolorized  with  a  few  drops  of  alcohol,  filtered,  one-third  the  weight 
