A  Au£Sf"  fjis"11'  )      Relative  Activity  of  Digitalis.  583 
Table  III. 
Guinea-pig  Assay  of  No.  30  Dirt  Sif tings  Separated  During  the  Process  of 
Cleaning  Digitalis— Ten  Per  Cent.  Infusion. 
Date  and  Time 
of  Test. 
No.  of 
Pig- 
Weight 
of  Pig. 
Dose  of 
Drug  in 
Gm.  per 
250  Gm. 
Wt.  of  Pig. 
Dose  of 
Drug  in  Gm. 
per  Gm.  Wt. 
of  Pig. 
Actual 
Given  in 
Mils  of  10  <fc 
Infusion. 
Results. 
2- 
-4-18.  12:50  A.M. 
6 
545 
•4 
.0016 
8.72 
Died   2-4-18,  9:00 
a.m.  8  hrs. 
2- 
-4-18,  I0:i8  P.M. 
II 
445 
•3 
.0012 
5-34 
Died    2-5-18,  4:30 
p.m.  18  hrs.  12  min. 
2 
-4-l8,  10:25  P.M. 
12 
370 
•25 
.0010 
3-7 
Died    2-5-18,  1:05 
p.m.  14  hrs.  40  min. 
2 
-4-I8,  12:40  A.M. 
s 
467 
.2* 
.0008* 
3-736 
Died  2-4-18,  11:50 
p.m.  33  hrs.  10  min. 
3 
-27-l8,  4:20  P.M. 
46 
375 
•175 
.0007 
2.625 
Recovered 
3 
-27-18,  4:25  P.M. 
47 
355 
•15 
.0006 
2.13 
Recovered 
According  to  Reed  and  Vanderkleed  the  standard  M.  L.  D.  for 
digitalis  is  100  milligrammes  of  drug  per  250  gramme  body  weight 
of  guinea  pig,  with  a  twenty-four-hour  limit.  Table  I  shows  that 
the  M.  L.  D.  of  the  select  cleaned  Minnesota  digitalis  was  43-75 
milligrammes  of  drug  per  250  gramme  body  weight  of  animal.  In 
other  words,  the  drug  proved  to  be  more  than  twice  as  active  as  re- 
quired by  the  arbitrary  standard  of  Reed  and  Vanderkleed,  which 
is  in  conformity  with  results  on  previous  years'  crops  of  Minnesota 
digitalis  when  tested  by  this  method.  This  table  also  shows  that  the 
activity  of  the  drug  from  which  the  petioles  had  been  partly  re- 
moved was  practically  the  same  as  that  of  the  entire  leaf. 
Table  II  clearly  indicates  that  the  petioles  of  digitalis  contain  a 
comparatively  small  amount  of  the  active  principles  of  the  drug.  The 
M.  L.  D.  was  225  milligrammes  of  petioles  per  250  gramme  body 
weight  of  pig.  The  petioles,  therefore,  were  only  about  one  fifth  as 
active  as  the  cleaned  drug,  and  two  fifths  as  active  as  the  arbitrary 
standard  requirement.  Post-mortem  examinations  showed  the 
hearts  to  be  systolic.  The  pigs  which  died  exhibited  the  usual  symp- 
toms caused  by  toxic  doses  of  digitalis.  The  removed  petioles  con- 
stituted about  sixteen  per  cent,  of  the  total  weight  of  the  drug  worked 
with  and  considering  their  low  activity  their  removal  would  only 
slightly  increase  the  activity  of  the  remaining  drug.  Theoretically 
the  activity  of  the  drug  with  petioles  partly  removed  was  increased 
*  M.  L.  D.  is  .2  Gm.  of  No.  50  dirt  siftings  per  250  Gm.  wt.  of  guinea-pig, 
or  .0008  Gm.  per  Gm.  wt.  of  guinea-pig. 
