534  Economy  of  Time  in  Percolation.      { A  AuguS  ?92*rm 
ECONOMY  OF  TIME  IN  PERCOLATION. 
By  Dr.  Robert  A.  Hatcher. 
{With  Technical  Assistance  of  Miss  Anna  Lichtman.) 
The  Pharmacopoeia  directs  that  when  an  official  tincture  is  to 
be  made  by  percolation  the  moistened  drug  shall  be  allowed  to  stand 
during  a  period  of  six  hours  before  it  is  packed  in  the  percolator, 
and  that  when  the  liquid  begins  to  drop  from  the  lower  orifice  of  the 
percolator,  the  drug  shall  be  allowed  to  macerate  during  a  period  of 
twenty-four  hours  before  the  percolation  is  allowed  to  proceed. 
It  is  desirable  that  the  moistened  drug  shall  not  stand  for  a  longer 
period  than  is  necessary  for  the  menstruum  to  penertate  thoroughly 
into  the  cells  before  being  packed  in  the  percolator,  and  that 
maceration  shall  not  then  continue  unless  it  is  necessary  for  the  ex- 
traction of  the  active  principles,  otherwise  time  is  wasted  and  alcohol 
is  lost  by  evaporation.  Furthermore,  the  longer  the  time  consumed 
in  making  tinctures  the  greater  is  the  investment  in  apparatus  and 
floor  space  required  for  a  given  number  of  operations  when  these 
are  sufficiently  numerous  to  demand  that  several  shall  be  conducted 
simultaneously.  This  is  a  matter  of  importance  to  large  manufac- 
turing pharmaceutical  establishments. 
It  is  probable  that  the  period  of  six  hours  during  which  the  moist- 
ened powder  stands  before  being  packed  in  the  percolator  suffices 
for  the  penetration  of  the  menstruum  into  the  cells  of  the  drug;  if 
this  is  not  the  case  the  fact  should  be  determined  by  experiment,  and 
a  greater  amount  of  menstruum  should  be  used  for  moistening  the 
powder,  or  it  should  be  allowed  to  stand  for  a  longer  period  of  time 
before  it  is  packed  in  the  percolator. 
Nux  vomica,  strophanthus,  and  aconite  powders  in  portions  of 
ioo  grammes  each  were  used  in  the  experiments  designed  to  show 
whether  it  is  necessary  to  macerate  the  powder  after  the  liquid  be- 
gins to  drop  from  the  percolator  in  the  preparation  of  the  official 
tinctures  of  these  drugs. 
The  percolation  of  the  nux  vomica  was  allowed  to  proceed 
(without  this  period  of  maceration)  until  iooo  cc.  of  percolate  were 
obtained,  and  the  marc  was  then  percolated  with  a  portion  of  the 
same  menstruum  until  500  cc.  of  weak  percolate  were  obtained.  The 
activity  of  the  tincture  and  that  of  the  weak  percolate  were  then  de- 
