4i8 
Digitalin. 
Am.  Jour.  Pharm. 
Aug.,  1892. 
minute.  The  presence  of  the  minutest  admixture  of  the  amorphous 
glucosides  is  at  once  revealed  by  the  rapid  appearance  of  an  intense 
yellow  coloration. 
(2)  When  digitalin  is  made  into  a  thin  paste  with  water,  and 
there  is  added  for  every  100  parts  of  water,  22  parts  amylic  alcohol, 
on  leaving  the  mixture  for  twenty-four  hours  in  a  closed  flask,  dis- 
tinct crystalline  warts  will  be  apparent  if  digitonin  be  present  even 
in  very  minute  proportion. 
Digitalin  is  almost  insoluble  in  chloroform  or  ether;  when  the 
moderately  dilute  solution  in  absolute  alcohol  is  gradually  mixed 
with  small  quantities  of  ether  the  liquid  suddenly  becomes  turbid, 
and  within  a  short  time  there  is  a  copious  deposition  of  digitalin 
granules.  On  pouring  off  the  solution  and  adding  to  it  more  ether 
a  second  point  of  saturation  is  reached,  and  with  it  a  further  depo- 
sition. The  same  effect  may  be  produced  a  third  time  or  more, 
and  this  behavior  is  evidence  of  the  purity  of  the  substance. 
Contrary  to  previous  statements  the  taste  of  digitalin  is  but 
slightly  bitter ;  the  intense  bitterness  and  very  disagreeable  taste 
previously  ascribed  to  digitalin  are  characters  belonging  to  the 
amorphous  glucosides  with  which  it  is  associated  in  digitalis. 
Digitalin  dissolves  in  concentrated  hydrochloric  or  sulphuric  acid 
with  a  golden  yellow  color,  and  in  the  latter  case  the  color  rapidly 
passes  into  blood  red.  On  adding  to  the  solution,  while  still 
yellow,  a  drop  of  nitric  acid,  ferric  chloride,  or  bromine  water,  a 
brilliant  purple  like  that  of  digitalis  flowers  is  produced,  but  the 
color  is  very  evanescent.  This  coloration  is  obtained  with  more 
certainty,  and  so  as  to  be  permanent  for  one  or  two  hours,  when 
a  very  small  quantity  of  digitalin  is  dissolved  in  ordinary  sulphuric 
acid  without  any  addition.  Probably  the  small  quantity  of  nitric 
acid  commonly  present  in  oil  of  vitriol  is  just  sufficient  to  produce 
the  coloration,  but  not  sufficient  for  causing  the  further  change 
which  appears  to  take  place  by  reason  of  the  presence  of  an  excess 
as  compared  with  the  digitalin  when  a  drop  of  the  oxidizing  agents 
is  added. 
Digitalin  remains  white  when  heated  to  2000 ;  at  2100  it  begins 
to  aggregate,  and  towards  2170  it  melts,  becoming  yellow-colored. 
Analysis  gave  results  agreeing  with  those  obtained  by  Schmiede- 
berg  which  lead  to  the  formula  (C5H802).  This  agreement  may  be 
taken  as  strong  evidence  that  Schmiedeberg's  digitalin  was  a  chemic- 
