PROPOSED  ECONOMY  OF  ALCOHOL  IN  PERCOLATION,  ETC.  Ill 
alcohol.  Thus,  by  stopping  the  percolation  at  the  point  indi- 
cated, thirty-one  cents  worth  of  product  is  lost,  but  seventy 
cents  worth  of  alcohol  is  saved,  and  this  reduces  the  value  or 
cost  of  the  diminished  product  obtained,  by  thirty-nine  cents. 
The  value  of  three-fourths  of  a  troyounce  would  then  be  fifty-five 
cents,  (or  73J  cents  per  troyounce,)  making  an  economy  in  value 
of  58  per  cent,  due  to  saving  in  alcohol  over  and  above  the 
value  of  the  extract  lost.  This,  too,  is  based  upon  the  assump- 
tion that  the  therapeutic  value  of  the  extract  is  the  same  from 
first  to  last, — an  assumption  quite  contrary  to  facts  obtained  in 
the  case  of  colchicum  seed,  to  be  hereafter  given. 
In  the  case  of  the  fluid  extracts,  the  problem  is  by  no  means 
so  easy  of  demonstration,  and  it  is  to  the  difficulties  attending 
the  application  of  the  same  plan  to  this  important  class  of  pre- 
parations that  this  paper  is  mainly  devoted.  The  alcohol  used 
as  directed  in  the  officinal  formulas,  even  when  carefully  recov- 
ered as  far  as  possible  by  distillation,  rarely  amounts  to  less  than 
one-fifth  of  the  total  cost  of  the  finished  preparation.  It  often 
amounts  to  one-third,  and  occasionally  to  one-half  or  more, 
and  this  in  operations  upon  a  large  scale.  In  the  hands  of  the 
dispensing  pharmaceutist  the  cost  is  far  greater. 
The  difficulties  in  applying  the  proposed  plan  to  this  class 
arise  mainly  from  the  necessity  that  the  finished  preparation 
shall  bear  to  the  drug  from  which  it  is  made,  the  definite  rela- 
tion of  a  minim  for  each  grain  in  effective  therapeutic  value. 
A  series  of  preliminary  experiments,  which  it  is  not  necessary 
to  detail,  proved  very  conclusively,  first,  that  in  exhaustion  by 
percolation  there  is  a  sufficient  degree  of  uniformity  of  results 
to  admit  of  the  adoption  of  a  model  plan  of  proceeding  appli- 
cable to  drugs  in  general ;  second,  that  the  extract  or  soluble 
matter  yielded  to  the  menstruum  is  not  uniform  in  its  chemical 
and  therapeutic  value  as  obtained  during  the  different  stages  of 
the  percolation,  but  diminishes  in  effective  value  far  more  rapidly 
than  the  extract  does  in  weight ;  and,  third,  that  this  decrease 
in  value  depends  upon  the  difference  in  solubility  between  the 
active  and  inactive  portions  of  the  extract,  and  that  the  ratio  of 
this  decrease  is  about  the  same  for  drugs  in  general,  provided 
the  proper  menstruum  be  used. 
