Am.  Jour.  Pharm. } 
July,  1878.  J 
Fluid  Extracts. 
329 
NOTES  ON  FLUID  EXTRACTS. 
By  Alonzo  Robbins,  Ph.G. 
The  subject  of  fluid  extracts  deservedly  continuing  to  attract  the 
attention  of  pharmacists,  the  following  experiments  were  undertaken 
with  the  hope  that  they  might  throw  some  light  on  the  question,  at 
least  so  far  as  concerned  the  drugs  operated  upon. 
The  substances  chosen  for  the  experiments  were  senna  and  seneka  ; 
the  senna  was  used  in  No.  40  powder,  and  the  seneka  in  No.  50.  The 
menstruum  employed  for  the  senna  was  made  of  1  part  alcohol,  sp.  gr. 
•822,  and  2  parts  water.  The  menstruum  used  for  the  seneka  was  com- 
posed of  150  parts  alcohol,  *822,  150  parts  water  and  10  parts  water  of 
ammonia.  Parts  by  weight  were  used  throughout.  The  use  of  parts  by 
weight  and  the  adoption  of  100  parts  of  the  drugs  as  the  standard  number 
to  be  taken,  which  allows  the  results  to  be  read  as  percentages  as  well 
as  parts,  presents  its  advantages  so  plainly  that  it  can  hardly  fail  of 
approbation. 
The  percolators  used  were  of  glass  and  made  specially  for  these 
experiments.  They  were  14  inches  high,  3!  inches  diameter  at  the 
top  and  f  inch  at  the  bottom.  When  in  use  the  lower  orifice  was 
closed  with  a  perforated  cork,  to  which  was  fitted  a  glass  tube  T\  inch 
diameter  and  2  inches  long.  To  the  glass  tube  a  rubber  tube  3  inches 
long  was  attached,  and  on  this  was  placed  a  pinchcock  to  control  the 
rate  of  percolation  and  to  stop  it  entirely  during  maceration. 
Moistening  and  Packing  of  the  Powder. — To  100  parts  of  the  powdered 
drug  from  35  to  40  parts  of  menstruum  were  added  and  thoroughly 
mixed,  and  the  mixture  passed  through  a  No.  18  sieve.  The  lower 
end  of  the  percolator  was  closed  with  a  cork,  and  on  this  was  placed  a 
loosely-fitting  plug  of  cotton.  The  moistened  powder  was  now  intro- 
duced in  small  portions,  each  portion  being  well  shaken  down,  and 
when  all  was  in  it  was  rather  firmly  packed  with  a  pestle  ;  the  surface 
of  the  powder  was  then  covered  with  a  thin  layer  of  cotton,  which  was 
kept  in  place  by  two  or  three  glass  stoppers.  The  cork  was  now 
removed  from  the  lower  aperture,  and  the  perforated  cork  containing 
the  glass  tube  put  in  place  and  the  percolation  proceeded  with  as 
described.  By  means  of  the  pinchcock  the  rate  of  dropping  was  kept 
at  from  4  to  8  drops  per  minute.  All  of  the  percolators  were  provided 
with  close-fitting  covers.  One  hundred  grams  of  the  moistened  powder, 
