33o 
Flid  Extracts. 
{Am.  Jour.  Pharm. 
July, 1878. 
when  packed  in  the  percolator,  occupied  a  space  from  7J  to  8  inches 
high. 
A  series  of  four  fluid  extracts  was  made  from  each  drug  and  the 
results  arranged  in  tabular  form,  the  better  to  allow  a  comparison  to 
be  made  of  the  various  stages  of  the  process.  On  another  more  con- 
densed table  is  shown  the  rate  or  percentage  of  exhaustion  in  those 
experiments  in  which  the  percolates  were  taken  in  twenty  portions. 
100  grams  of  powder  was  used  for  each  experiment. 
Experiment  No.  1. — As  soon  as  the  powder  was  packed  menstruum 
was  added,  and  the  percolation  allowed  to  proceed  at  once  without 
maceration.  The  percolate  was  taken  in  portions  of  25  grams  each 
until  20  portions  or  500  grams  in  all  had  been  obtained,  then  the  per- 
colation was  continued  until  500  grams  more  had  passed,  which  was 
collected  in  one  portion. 
Experiment  No.  2. — When  the  powder  was  packed  menstruum  was 
added,  and  when  the  percolate  appeared  in  the  cotton  plug  the  lower 
aperture  was  closed  and  maceration  continued  four  days,  and  then  the 
percolate  was  taken  in  portions  as  in  experiment  No.  1. 
Experiment  No.  3  was  intended  to  show  what  effect  repeated  macera- 
tion would  have  in  the  exhaustion  of  soluble  matter  from  the  substances 
operated  upon.  When  the  percolate  appeared  in  the  cotton  plug  the 
lower  aperture  was  closed,  and  maceration  was  continued  four  days, 
then  25  grams  of  percolate  was  obtained,  and  then  the  percolator 
again  closed  and  maceration  continued  three  days,  when  25  grams  more 
of  percolate  was  obtained  ;  the  percolator  was  now  closed  for  two  days, 
and  then  25  grains  percolate  obtained.  It  was  now  closed  one  day, 
and  then  allowed  to  proceed  without  interruption  until  the  full  number 
of  20  percolates  were  obtained  and  the  final  500  grams. 
Experiment  No.  4. — This  experiment  was  intended  to  corroborate 
the  results  obtained  by  experiment  No.  1.  The  percolation  was  allowed 
to  proceed  without  maceration,  and  at  a  more  rapid  rate  ;  the  percolate 
was  taken  in  two  portions  of  500  grams  each.  The  greater  specific 
gravity  shown  by  this  fluid  extract  is  not  due  to  its  containing  more  dry 
extract  than  the  others,  but  is  caused  by  the  entire  percolate  being 
evaporated  until  reduced  to  100  parts,  thereby  driving  off  all  or  nearly 
all  of  the  alcohol,  while,  in  the  other  experiments,  the  first  75  parts  of 
percolate  were  reserved  and  not  subjected  to  any  evaporation. 
