A  August  ?92irm* }      Economy  of  Time  in  Percolation.  535 
termined  by  means  of  the  biologic  test  on  frogs.  The  protocol  of  the 
experiment  (in  brief)  which  follows  shows  the  tincture  represented 
the  drug  almost  completely,  and  that  the  activity  of  the  weak  per- 
colate was  equal  to  only  about  I  per  cent,  of  that  of  the  tincture. 
PROTOCOL  (IN  BRIEF). 
One  hundred  grammes  of  nux  vomica  in  No.  60  powder  were 
moistened  with  menstruum  consisting  of  a  mixture  of  three  volumes 
of  alcohol  and  one  volume  of  water;  the  moistened  drug  was  trans- 
ferred to  a  percolator  and  allowed  to  stand  three  hours  (instead  of 
six  hours,  as  directed  by  the  Pharmacopoeia),  after  which  it  was 
packed  firmly,  menstruum  was  added  and  percolation  was  allowed 
to  proceed  at  once  until  a  total  of  1000  cc.  of  percolate  was  obtained 
in  a  period  of  forty-four  hours.  Percolation  of  the  marc  was  con- 
tinued until  500  cc.  of  weak  percolate  were  obtained. 
The  activity*  of  the  tincture  and  that  of  the  weak  percolate  were 
estimated  by  determining  the  amounts  required  to  kill  a  given 
weight  of  frogs  after  injection  into  the  lymph  sac.  The  tests  showed 
that  1000  cc.  of  the  tincture  would  suffice  to  kill  about  400  kilos  of 
frogs,  and  that  the  weak  percolate  would  suffice  to"  kill  about  2.5 
kilos.  This  shows  that  the  activity  of  the  weak  percolate  was  less 
than  1  per  cent,  of  that  of  the  tincture.1 
The  results  of  this  experiment  show  that  it  is  not  necessary  to 
macerate  nux  vomica  after  the  liquid  begins  to  drop  from  the  per- 
colator in  order  to  insure  the  practically  complete  exhaustion  of  the 
drug  when  making  the  official  tincture,  provided  the  moistened  pow- 
der has  been  allowed  to  stand  for  a  period  of  several  hours  before 
being  packed  in  the  percolator. 
It  seemed  desirable  tp  compare  the  activity  of  the  first  portion 
of  percolate  and  that  of  the  finished  tincture  made  in  the  manner 
just  described  with  the  activity  of  the  weak  percolate,  hence  the 
procedure  was  modified  in  the  preparation  of  the  tinctures  of  stro- 
phanthus  and  aconite.  A  portion  of  250  cc.  of  the  first  percolate  of 
each  of  these  was  put  aside,  and  percolation  was  allowed  to  proceed 
1  Frogs  usually  require  about  5.5  mg.  of  strychnin  sulpate  per  kg.  of 
weight  to  cause  death  when  the  poison  is  injected  into  the  lymph  sac  in 
solution  containing  1  part  of  the  poison  to  1000  parts  of  normal  salt  solu- 
tion. Some  lots  of  frogs  show  closely  concordant  results,  whereas  others 
show  greater  individual  differences.  The  results  in  this  experiment  were 
not  exactly  uniform,  but  the  agreement  was  sufficiently  close  for  the  pur- 
poses of  this  investigation. 
