METHOD  OF  PERCOLATION  FOR  FLUID  EXTRACTS. 
17 
A  SUPPLEMENT  TO  CAMPBELL'S  METHOD  OF  PERGOLA- 
TION  FOR  FLUID  EXTRACTS. 
By  Samuel  Campbell,  of  Philadelphia. 
To  THE  Editor  : 
In  the  September  number  of  the  American  Journal  of  Phar- 
macy, I  published  an  article  entitled  "  a  new  and  simple  pro- 
cess for  fluid  extracts,  by  which  any  drug  may  be  exhausted  by 
percolation  and  without  heat,"  and  as  I  learn  that  there  seems 
to  be  some  misunderstanding  regarding  the  minutiae  of  the 
method  proposed,  I  herewith  take  the  liberty  of  presenting  to 
you  for  publication  a  second  paper,  on  the  same  subject,  em- 
bracing an  analysis  of  each  step  of  the  process,  with  a  classifi- 
cation of  a  list  of  the  fluid  extracts  made  by  this  method  in  a 
series  of  experiments  made  by  myself.  The  subject  is  an  im- 
portant one,  and  one  that  is  worthy  the  attention  of  the  revisers 
of  the  Pharmacopoeia,  recommending  itself  by  its  simplicity  of 
manipulation  and  formula,  involving  no  expense  by  waste,  nor 
outlay  of  means  for  vessels,  or  stills,  wherewith  to  recover  al- 
cohol, and  requiring  only  ordinary  care  and  skill  to  make  a 
perfect  fluid  extract.  It  also  leaves  the  retail  pharmaceutist 
without  excuse  in  not  making  the  fluid  extracts  himself,  in 
preference  to  buying  them  from  the  manufacturer,  as,  by  this 
method,  he  may  prepare  as  small  a  quantity  as  four  fluid 
ounces,  or  as  large  a  quantity  as  desired  ;  as  I  experienced 
better  success  in  making  five  pints  than  in  making  a  half  pint, 
the  smaller  quantity  requiring  more  careful  manipulation  than 
the  larger,  a  point  which  will  recommend  itself  to  the  manufac- 
turing pharmaceutist.  The  first  step  in  the  process  is  to  obtain 
a  powder  of  the  proper  degree  of  fineness,  a  point  upon  which 
there  seems  to  be  a  difi'erence  of  opinion  among  pharmaceutists ; 
some  maintaining  that  it  is  not  necessary  to  have  a  fine  or  very 
fine  powder  for  purposes  of  percolation  ;  others  taking  the  con- 
trary view,  that  a  powder  cannot  be  too  fine.  In  my  opinion, 
much  harm  has  been  done  by  the  advocates  of  extremely  fine 
powders,  as  it  has  a  tendency  to  throw  the  whole  business  of 
making  officinal  fluid  extracts  into  the  hands  of  the  manufac- 
turers, or  compels  the  conscientious  retailer,  who  prefers  to  make 
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