208 
Keeping  Properties  of  Digitalis. 
(  Am.  Jour.  Pharm. 
\       May,  1913. 
completely  filled  glass  containers,  protected  from  light  and  moisture. 
In  spite  of  the  general  consensus  of  opinion  to<  the  effect  that 
age,  moisture,  light,  and  heat,  alone  or  variously  combined,  accord- 
ing to  the  observer,  cause  marked  and  rapid  deterioration  in  digi- 
talis leaves  and  alcoholic  fluid  preparations,  we  long  since  came  to 
a  contrary  opinion,  for  we  had  observed  that  samples  of  powdered 
leaf  which  had  been  in  the  laboratory  in  cardboard  containers  for 
several  years,  and  tinctures  prepared  from  these  leaves  at  different 
times  in  the  past  few  years,  retained  their  activity  almost,  if  not 
quite,  unimpaired.  Stimulated  by  this  apparent  anomaly,  we  under- 
took an  investigation  of  the  question  of  deterioration  of  digitalis 
leaf  and  some  of  its  preparations. 
We  began  by  making  new  tests  of  the  activity  of  our  own  old 
samples  of  the  leaf  and  of  tinctures  made  therefrom.  Comparing 
the  results  of  these  tests  with  the  records  of  previous  ones,  we 
found  that  none  of  the  specimens  which  were  four  or  five  years  old 
showed  any  material  deterioration.  These  samples  of  leaf  and 
tincture  had  been  kept  without  any  special  care,  the  tinctures  being 
stored  in  glass-stoppered  bottles  and  exposed  to  the  light  and  tem- 
perature changes  of  the  laboratory.  The  leaf,  as  has  been  men- 
tioned, was  kept  in  the  original  cardboard  containers,  and  not 
protected  in  any  way  from  either  heat  or  moisture  changes  as  these 
occurred  in  the  atmosphere  of  the  laboratory,  but  it  should  be  said 
that  the  storeroomi  is  unusually  dry  for  this  climate.  The  cat  method 
was  employed  for  the  estimation  of  the  activity  of  the  specimens, 
and  in  some  few  instances  we  also  used  the  one  hour  frog  method 
with  results  quite  in  accord  with  those  obtained  with  the  cat.  We 
sought  to  obtain  some  older  specimens  than  ours,  and,  through  the 
courtesy  of  E.  R.  Squibb  &  Sons,  and  Gilpin,  Langdon  &  Company, 
we  were  supplied  with  samples  of  the  leaf,  ground  and  unground, 
tinctures,  extracts,  and  fluid  extracts  ranging  from  less  than  one 
to  more  than  thirty  years  old.  With  some  of  these  we  conducted 
tests  on  both  cats  and  frogs. 
A  sample  of  German  digitalis  which  had  been  kept  in  paper 
for  three  years  on  a  jobber's  shelf  was  received  in  the  form  of  No. 
60  powder  and  was  foimd  to  contain  7.5  per  cent,  of  moisture.  It 
gave  a  cat  unit  of  110  mg.  per  kilo  of  cat  weight.  A  sample 
of  English  leaf  in  fine  powder,  which  had  been  kept  on  a  shelf  in 
paper  for  three  years,  gave  a  cat  unit  of  128  mg.,  and  it  contained 
6  per  cent,  of  moisture.   Both  of  these  were  considered  by  the  jobbers 
