Am.  Jour.  Pharm.  \ 
March,  1919.  > 
Digitalis  Leaves. 
179 
Hatcher  and  Eggleston10  found  that  old  samples  of  digitalis 
leaves  and  tinctures,  neither  of  them  specially  preserved,  were  not 
much  below  their  original  activity.  They  concluded  that  fluid  prep- 
arations containing  not  less  than  50  per  cent,  alcohol  do  not  de- 
teriorate to  any  considerable  degree.  This,  however,  is  not  in  ac- 
cord with  most  investigators,  although  the  higher  strengths  of 
alcohol  are  in  general  much  better  for  preserving  the  activity. 
Houghton  and  Hamilton,11  in  a  series  of  tests  and  retests  of 
digitalis  extracts,  showed  that  none  of  them  is  free  from  the  fault 
of  deterioration,  their  results  pointing  to  the  apparent  fact  that  the 
higher  percentages  of  alcohol  not  only  more  completely  extract  but 
also  more  thoroughly  preserve  the  active  principles. 
On  the  supposition  that  the  strong  alcohol  destroys  the  active 
ferments  these  results  are  in  accord  with  the  results  of  Perrot  and 
Goris,12  who  published  a  method  by  which  the  enzymes  could  be 
destroyed  with  the  subsequent  complete  preservative  of  the  drug  in 
its  original  activity.  This  was  accomplished  by  subjecting  the  drug 
to  the  vapors  of  boiling  alcohol  after  which  it  was  dried  in  the  air. 
Such  precautions,  however,  seem  unnecessary  in  view  of  the  results 
with  old  samples  of  digitalis  obtained  by  the  different  investigators 
quoted,  especially  Hatcher,  who  found  high  values  in  25-year-old 
leaves,  and  Sharp  and  Lancaster,  who  found  11-year-old  drug  to 
have  lost  little  of  its  activity. 
The  writer  recently  had  occasion  to  extract  and  test  a  sample 
which  had  been  in  the  possession  of  Northwestern  University  for 
twenty-five  years.  Its  activity  was  fully  150  per  cent,  of  that  of 
the  average  drug  at  present  obtainable. 
Recently  the  subject  of  drying  digitalis  leaves  has  come  up  in 
connection  with  the  samples  of  this  drug  grown  wild  in  Oregon  and 
submitted  to  the  government  for  the  Medical  Department  of  the 
Army.  It  was  stated  that  unless  the  drug  was  dried  in  an  oven,  at 
75  to  900,  it  was  practically  worthless. 
This  statement  being  so  entirely  at  variance  with  the  opinions 
commonly  held,  some  experiments1  were  inaugurated  to  demonstrate 
its  correctness.  Unfortunately,  there  was  not  available  a  sufficient 
amount  of  the  growing  digitalis  leaves  to  make  the  experiments  con- 
10  Hatcher  and  Eggleston,  Am.  J.  Pharm.,  85,  203,  1913. 
11  Houghton  and  Hamilton,  ibid.,  81,  461,  1909. 
12  Perrot  and  Goris,  Abs.  in  La  Presse  Medicale,  17,  776,  1909. 
