io6 
P  hysiol  o  gic  a  I  Standard  iza  Hon. 
f  Am.  Jour.  Ph&rm. 
\      March,  1910. 
of  storing;  if  the  leaves  were  dried  in  vacuo  at  a  temperature  of 
about  i ocr  and  afterwards  hermetically  sealed,  they  retained  their 
activity  unimpaired  for  a  long  period  of  time.  Dixon  and  Haynes 
were  unable  to  observe  any  deterioration  in  a  tincture  of  digitalis 
which  was  kept  for  four  months  without  special  precaution.  Hough- 
ton found,  however,  that  the  present  official  liquid  preparations  of 
digitalis  lost  about  10  per  cent,  a  year,  although  the  tincture  of 
strophanthus  seemed  permanent.  A  higher  percentage  of  alcohol 
than  at  present  required  seemed  also  to  be  shown  by  his  work  to 
be  desirable. 
Bennefield  made  an  attempt  to  determine  the  quality  of  digitalis 
tincture  by  the  percentage  of  the  solid  extractive  matter  which  it 
contained,  but  found  that  this  bore  no  relation  to  the  physiological 
activities  of  the  drug.  In  1895  Keller  described  a  method  for  the 
chemical  assay  of  digitalis,  based  upon  its  percentage  of  digitoxin. 
Ziegenbein.and  also  Famulener  and  Lyons,  found,  however,  by  means 
of  biological  tests  that  Keller's  method  of  assay  was  unreliable.  In 
1904,  Barger  and  Shaw  confirmed  these  findings,  and  showed  that 
the  inaccuracy  of  Keller's  method  depended  upon  three  facts :  first, 
that  it  did  not  extract  all  the  digitoxin ;  second,  that  it  did  not  iso- 
late the  digitoxin  in  a  pure  condition :  third,  that  digitoxin  is  not  the 
only  active  ingredient  of  digitalis.  Which  reminds  me  of  the  story 
of  the  little  girl,  who  when  asked  if  she  was  going  to  Maggie  Jones's 
party  said,  "  No.  she  did  not  like  Maggie  Tones,  she  had  nothing 
to  wear  and  besides  she  was  not  invited." 
This  hasty  summary  of  what  has  been  done  through  biological 
assay  of  digitalis  seems  to  me  to  show  great  advancement  in  our 
knowledge  of  an  extraordinary  complex  subject,  for  while  we  may  be 
disappointed  at  the  slowness  of  the  progress  it  is  undeniable  that 
great  advance  has  been  made.  Of  the  questions  which  we  saw 
were  within  the  province  of  the  assayer  to  consider,  all  have  been 
answered,  if  not  with  absolute  finality,  yet  within  the  limits  of 
scientific  probability,  except  only  the  means  of  standardizing  the  drug 
chemically.  He  has  told  you  how  you  may  distinguish  between 
active  and  feeble  samples  of  digitalis,  he  has  told  you  where  grow 
the  best  quality  of  leaves,  when  to  gather  them  and  how  to  keep 
them  with  the  minimum  of  deterioration,  he  has  told  you  the  best 
menstruum  to  extract  their  virtues  and  of  the  necessity  of  dating 
digitalis  galenicals.  I  am  convinced  that  did  the  pharmacist  but 
hearken  to  the  advice  of  the  pharmacologist  as  to  the  manufacture 
