20  The  Strength  of  I  liiid  Extracts,  {^janTisn!'''' 
course,  with  the  varying  amount  of  soluble  medicinal  matter  contained 
in  different  drugs ;  but,  as  a  rule,  adapted  to  the  treatment  of  drugs 
generally  on  the  small  scale,  and  in  an  ordinary  displacement  funnel, 
three  pints  of  percolate  for  every  sixteen  troy  ounces  of  drug,  although 
excessive  in  some  cases,  no  doubt  is  yet  the  safest  for  general  use. 
Were  the  percolation  stopped  at  two  pints  of  percolate  for  every  six- 
teen ounces  of  drug,  the  resulting  preparation  would,  in  most  cases, 
be  simply  a  concentrated  tincture,  representing  no  definite  quantity 
of  drug, — superior,  perhaps,  to  many  of  the  so-called  fluid  extracts 
of  the  market,  but  by  no  means  to  be  considered  a  true  representative 
of  the  original  drug.  Doubtless  there  are  physicians  to  whom  the 
excess  of  alcohol  would  not  be  an  objectionable  feature,  and  who 
would  prefer  such  concentrated  tinctures,  prepared  by  the  apothecary 
himself,  to  the  uncertain  products  of  the  market.  It  might  be  well 
enough  therefore  (although  the  writer  does  not  recommend  it),  to 
introduce  them  into  the  Pharmacopoeia,  under,  however,  a  separate 
and  distinct  title,  such  as  Tincturse  Fortiores,  retaining  Extracta 
Fluida  for  the  many  physicians  who  dislike  to  prescribe  alcohol,  except 
in  minimum  doses. 
The  following  formulas  illustrate  the  ideas  of  the  writer  on  this 
subject  : 
Extraetwn  Buchu  Fluidum. 
Take  of  Buchu,  sixteen  troy  ounces. 
Glycerin,  four  fluid  ounces. 
Alcohol  and  Water,  sufiicient. 
Grind  the  buchu,  and  sift  it  successively  through  No.  20,  No.  40, 
and  No.  60  sieves,  keeping  the  result  of  each  sifting  separate.  Mix 
the  glycerin  with  twenty  fluid  ounces  of  the  alcohol,  and  with  five 
fluid  ounces  of  this  menstruum  moisten  the  different  lots,  and  intro- 
duce them  successively  into  the  percolator,  commencing  with  the 
finest ;  pack  firmly,  and  gradually  pour  on  the  remainder  of  the  alco- 
hol and  glycerin,  following  it  with  a  mixture  of  alcohol  and  water  in 
the  same  proportion,  till  the  drug  ceases  to  absorb  any  more  and  the 
menstruum  remains  permanently  on  the  surface  ;  then,  having  closed 
the  orifice  of  the  pecolator  with  a  cork  and  put  on  the  cover,  set  aside 
to  macerate.  At  the  end  of  twenty  four  hours,  or  longer,  remove  the 
cork  and  allow  the  percolation  (which  should  not  be  faster  than  ten 
drops  per  minute)  to  proceed.    When  the  liquid  has  disappeared  from 
