Am.  Jour.  Pharm. 
March,  1913. 
}    Standardization  of  Digitalis  Bodies.  119 
plete  preparation  of  each  of  the. animals.  It  was  a  very  simple 
matter  for  the  operator,  aided  by  the  laboratory  boy,  to  administer 
a  few  drops  of  ether  from  time  to  time  as  the  individual  animals 
required,  and  at  the  same  time  to  watch  and  control  the  rate  of  the 
several  injections.    The  results  are  given  in  Table  4. 
Table  4- 
Standardization  of  Ithaca  Cats. 
Cat 
Sex 
Weight  in  Kg. 
Duration  of  injection 
in  minutes 
Dose  of  ouabain 
Mg.  X  Kg. 
I 
f 
2.04 
72 
O.09 
2 
f 
2.38 
72 
O.09 
3 
f 
2.00 
84 
O.09 
4 
m 
4-32 
71 
O.085 
5 
f 
i-47 
74 
O.098 
6 
m 
1.61 
92 
O.099 
7 
f 
2.20 
83 
O.084 
8 
f 
1.44 
52 
O.IIO 
The  total  time  consumed  in  the  estimations  on  these  8  cats  from 
the  beginning  of  the  first  anesthesia  to  the  death  of  the  last  animal 
was  one  hour  and  fifty-seven  minutes  and  no  special  effort  was 
made  in  the  matter  of  haste.  The  average  duration  of  injection 
was  75  minutes  and  the  average  dose  of  ouabain  required  was 
0.093  mg-  Per  kg.  of  cat  weight,  a  figure  only  7  per  cent,  below 
the  established  cat  unit.  The  greatest  variation  from  the  average 
is  18.2  per  cent,  above,  and  this  was  obtained  from  the  only  animal 
which  did  not  seem  quite  normal  before  the  tests  were  begun,  being 
considerably  depressed  and  not  at  all  lively  or  vigorous. 
The  last  animal  died  at  12.12  P.M.,  three  hours  after  prepara- 
tions were  begun  for  the  tests,  another  20  minutes  was  required 
for  the  calculation  of  the  doses  taken  by  the  animals.  Three  hours 
and  a  half  may  be  taken  as  the  extreme  limit  of  time  needed  for 
this  series  of  8  tests. 
How  does  this  compare  with  the  other  methods  as  regards  the 
element  of  time  required  ?  The"  twelve  hour  frog  method,  obviously, 
cannot  be  done  in  less  than  twelve  hours.  The  one  hour  frog 
method  would  require  at  least  15  minutes  for  the  preparation  of  the 
solution  and  the  weighing  of  the  frogs,  together  with  their  in- 
jection. It  usually  requires  the  use  of  at  least  three  groups  of 
frogs  for  an  accurate  determination,  each  group  requiring  one  hour, 
the  total  time  for  an  assay  would  then  scarcely  fall  within  less  than 
three  hours  and  a  half. 
