400 
PHARMACY  OF  THE  CINCHONAS. 
The  first  experiments  were  made  with  mixtures  in  various 
proportions,  of  alcohol  and  glycerin  as  a  menstruum,  but  it  was 
found  that  where  less  than  the  present  officinal  measure  was  to 
be  the  result  these  mixtures  were  not  easily  practicable,  and  that 
even  with  the  present  measure  for  the  fluid  extract  the  manage- 
ment was  difficult  and  tedious.  A  percolator  with  but  twice  the 
officinal  quantity,  and  not  tightly  packed,  and  managed  by  Mr. 
Taylor's  formula,  with  a  menstruum  of  equal  measures  of  alcohol 
and  glycerin,  has  now  stood  upon  the  writer's  table  since  near 
the  commencement  of  these  experiments.  From  April  15th  to 
May  23d  was  required  for  liquid  to  reach  the  lower  end  of  the 
percolator,  and  now,  June  11th,  the  amount  of  percolate  accu- 
mulated in  the  flask  does  not  amount  to  more  than  four  fluid- 
ounces.  As  the  weather  grows  warmer  the  rate  increases  a  lit- 
tle, but  the  prescribed  measure  will  hardly  be  received  before 
the  autumn.  The  percolate  is  very  peculiar,  and  the  exhaustion 
will  be  sudden  and  perfect  with  the  very  smallest  possible  quan- 
tity of  menstruum,  for  it  is  an  axiom  in  percolation  that  the 
slower  it  is  performed  the  more  perfect  and  sudden  is  the  ex- 
haustion, and  with  the  smallest  quantity  of  menstruum.  With 
a  conical  percolator,  however,  without  packing,  but  with  only  a 
gentle  compression  of  the  moistened  powder  after  it  is  all  in  the 
funnel,  and  in  warm  weather,  a  very  nice  preparation  of  the 
officinal  measure  may  be  obtained  by  Mr.  Taylor's  process,  if  the 
one  to  be  offered  further  on  be  not  admitted  as  preferable.  In 
this  the  use  of  glycerin  in  the  menstruum  is  given  up,  as  being 
difficult  and  without  any  compensating  advantage,  since  both 
alcohol  and  diluted  alcohol  were  proved  to  exhaust  the  bark  as 
perfectly  when  used  alone  as  when  mixed  with  the  glycerin. 
That  is,  the  proper  function  and  uses  of  the  glycerin  being  to 
preserve  the  preparation  rather  than  to  extract  the  Cinchona,  it 
is  added  where  its  usefulness  begins, — namely,  after  the  extrac- 
tion of  the  bark.  This  point  established,  it  next  became  ne- 
cessary to  decide  between  alcohol  (officinal  s.  g.  *835,  or  85  p.  c.) 
and  diluted  alcohol  (officinal  s.  g.  -941,  or  39  p.  c),  as  the  best 
menstruum  by  which  to  extract  the,  medicinal  properties  of  the 
Cinchonas  ;  and  in  the  investigation  of  this  question  it  must  be 
borne  in  mind  that  the  best  menstruum  not  only  involves  the 
