^^i'tmC""'}      The  Strength  of  Fluid  Extracts,  19 
the  inch, — repeating  the  operation  two  or  three  times,  or  so  long  as 
any  fine  powder  is  obtained.  In  packing  for  percolation  the  powders 
are  arranged  in  the  order  of  their  fineness,  commencing  with  the 
finest — thus  exposing  the  least  permeable  portions  of  the  drug  to  the 
most  solvent  portions  of  the  menstruum,  and  also  ensuring  a  slow  rate 
of  percolation,  so  essential  to  a  successful  result.  Operating  in  this 
way,  perhaps  a  little  more  menstruum  is  required  than  if  the  drug 
were  in  ''moderately  fine"  powder,  as  directed,  but  then  the  process 
is  brought  within  the  range  of  practicability,  while  before  it  was  not. 
The  low  degree  of  temperature  directed  for  the  evaporation  of  the 
percolate  furnishes  another  ground  for  reasonable  objection  to  the 
ofiicinal  processes,  on  account  of  the  waste  of  alcohol,  the  temperature 
specified  not  permitting  of  its  recovery  by  distillation.  Economically 
considered,  and  on  the  scale  of  the  Pharmacopoeia,  this  objection 
hardly  has  any  weight,  as  the  waste  would  be  but  trifling ;  on  any 
larger  scale,  however,  the  saving  of  the  alcohol  becomes  a  matter  of 
some  economical  importance,  and  its  recovery  therefore,  by  distillation 
in  a  water  bath  still,  should  receive  the  sanction  of  the  Pharmacopoeia. 
No  appreciable  injury  to  the  medicinal  matter  can  result  from  the 
necessary  increase  of  temperature,  as  this  would  be  more  than  coun- 
terbalanced by  the  more  perfect  exclusion  of  atmospheric  influences. 
With  these  modifications  of  the  formulas  surely  the  preparation  of 
fluid  extracts,  of  the  strength  of  sixteen  troy  ounces  of  drug  to  the 
pint,  is  not  a  very  diflicult  matter.  The  apparatus  required  is  exceed- 
ingly simple,  a  drug  mill,  a  set  of  sieves,  a  percolator,  and  a  water- 
bath  still  being  all  that  is  necessary.  Is  there  a  druggist  in  the  land 
who  considers  his  vocation  anything  more  than  the  mere  buying  and 
selling  of  drugs,  not  already  possessed  of  these  necessary  implements 
of  his  art?  Scientifically  considered  a  simple  matter,  the  correct 
preparation  of  a  fluid  extract  does  involve  strict  care  and  attention, 
and  a  conscientious  selection  of  the  crude  material.  No  amount  of 
science  will  atone  for  poor  material  or  careless  manipulation. 
The  proposed  reduction  of  strength,  it  is  claimed,  would  ensure  the 
complete  exhaustion  of  the  drug.  In  a  limited  number  of  instances, 
doubtless,  this  claim  would  hold  good, — in  drugs,  for  example,  like 
ginger,  which  yield  their  medicinal  matter  easily  and  readily  to  a  sol- 
vent ;  but  that  senna,  rhubarb,  cinchona,  or  drugs  generally,  can  be 
exhausted  in  this  way,  is  altogether  contrary  to  the  writer's  experience. 
Just  the  amount  of  menstruum  necessary  for  exhaustion  varies,  of 
