6  ECONOMY  IN  THE  USE  OF  ALCOHOL  IN  PERCOLATION. 
seven-tenths  of  a  grain  of  resin  precipitated  from  the  8th  portion 
of  the  percolate,  was  swallowed  under  the  same  conditions. 
The  effect  on  the  following  day  was  but  little,  if  at  all  greater 
than  from  the  fourth  of  a  grain  of  the  unseparated  or  normal 
resin.  Then,  after  an  interval  of  more  than  two  months  to  allow 
the  effects  to  pass  off  entirely,  the  filter  containing  the  one  and 
five-tenths  grains  of  resin  from  the  7th  portion  of  the  percolate 
was  swallowed  under  the  same  conditions  as  before.  The  effect 
of  this  dose  was  more  than  aperient  or  laxative,  but  was  only 
moderately  purgative,  commencing  its  action  no  earlier  than  the 
other  doses,  and  ending  about  twenty-nine  hours  after  the  taking. 
This  effect  was  estimated  as  about  three  times  that  of  the  former 
filter,  or  at  most  four  times  the  effect  of  the  fourth  of  a  grain  of 
unseparated  resin.  As  far  as  these  experiments  can  be  relied 
on,  then,  they  tend  to  show  that  the  purgative  quality  of  the 
resin  diminishes  more  rapidly  than  the  quantity,  the  next  to  the 
last  portion  requiring  six  times  the  quantity  to  produce  four 
times  the  effect,  and  the  last  portion  requiring  nearly  three  times 
the  quantity  to  produce  the  same  effect,  as  the  fourth  of  a  grain 
of  the  normal  resin. 
Thus,  in  the  progress  of  the  percolation,  whilst  the  resin  di- 
minishes very  rapidly  in  its  relation  of  ratio  to  the  extract,  it 
also  diminishes  rapidly  in  medicinal  effect  for  a  given  quantity, 
so  that  it  is  doubtful  whether  that  obtained  after  the  first  pint 
be  worth  the  time  and  trouble  of  extraction.  If  the  cost  of 
menstruum  be  admitted  into  the  account,  however,  it  becomes 
altogether  unimportant.  It  follows,  from  these  considerations, 
that  the  formula  for  the  officinal  extract  of  Podophyllum,  like 
that  for  the  corresponding  extract  of  Jalap,  is  very  wasteful  in 
menstruum  and  in  time,  and  yields  a  product  encumbered  with 
much  useless  matter. 
The  seventh  and  final  series  in  the  experiments  upon  Podo- 
phyllum was  undertaken  to  determine  the  details  of  a  proper 
working  formula,  which  should  yield  a  uniform  and  good  product 
with  the  greatest  economy,  convenience  and  ease,  in  the  hands 
of  those  not  specially  educated  to  it  by  practice ;  and  the  results 
are  given  in  the  following  formula : 
