Am-^r-1^arm-}       Keeping  Properties  of  Digitalis.  213 
the  ventral  lymph  sac  of  each  of  three  frogs.  The  first  weighed 
14.5  gm.  and  received  0.25  c.c.  total,  the  second  21.0  gm.  and  re- 
ceived 0.5  c.c.  total,  and  the  third  weighed  21.5  gm.  and  was  in- 
jected with  1.0  c.c,  an  amount  equal  to  about  5000  rag.  per  kilo 
of  frog.    None  of  the  frogs  died. 
A  second  sample  of  acetic  fluid  extract  of  digitalis  was  tested 
to  see  if  a  fresh  preparation  was  active.  This  sample  was  made  on 
January  16,  191 3,  and  was  tested  on  the  29th  of  the  same  month, 
only  thirteen  days  after  its  preparation.  It  was  found  to  have  a 
cat  unit  of  925  mg.  per  kilo,  or,  roughly,  it  had  only  about  10 
per  cent,  of  its  supposed  activity. 
From  the  foregoing  it  is  obvious  that  this  preparation  is  worth- 
less. This  is  only  what  is  to  be  expected,  for  the  decomposition 
of  glucosides  by  dilute  acids  is  universally  recognized. 
In  addition  to  these  tests  of  the  leaf  and  galenical  preparations 
we  have  tested  some  of  the  proprietaries  with  reference  to  their 
deterioration.  One  of  these,  which  has  been  claimed  to  be  perma- 
nent, namely  Digalen  (liquid),  gave  the  following  results: 
Two  specimens  obtained  in  191 2  were  tested  at  the  same  time 
and  one  gave  a  cat  unit  of  1.52  c.c.  per  kilo,  while  the  other  gave  a 
unit  of  2.45  c.c.  per  kilo.  A  specimen  obtained  in  1908,  and  kept 
sealed  as  originally  sent  out,  gave  a  cat  unit  of  approximately  3.0 
c.c.  per  kilo  when  tested  in  November,  19 12.  In  the  case  of  the 
first  two  specimens,  obtained  fresh  at  the  same  time,  the  stronger 
was  almost  100  per  cent,  more  active  than  the  weaker.  The  speci- 
men of  1908  was  only  about  half  as  active  as  the  one  of  1912.  It  is 
fair  to  assume  that  all  of  the  batches  of  digalen  are  originally  made 
of  the  same  activity,  and  if  this  assumption  be  correct  this  prepara- 
tion is  subject  to  far  more  rapid  deterioration  than  either  the  digi- 
talis leaf  or  its  galenical  preparations,  which  contain  50  per  cent, 
or  over  of  alcohol.  The  examples  cited  are  but  representative  of 
our  results  with  many  different  specimens  of  digalen. 
It  remains  for  us  to  discuss  briefly  some  of  the  opposed  findings 
here  recorded. 
All  whose  observations  have  been  cited  used  frogs  exclusively 
as  the  test  animals  in  their  determinations.  Cloetta  has  contended 
that  fresh  digitalis  contains  little  or  no  digitoxin,  but  that  this 
constituent  is  developed  during  storage.  It  is  known  that  digitoxin 
is  irregularly  and  relatively  slowly  absorbed  from  the  lymph  spaces 
of  the  frog.    If  Cloetta's  contention  is  correct  the  development  of 
