120   PROPOSED  ECONOMY  OF  ALCOHOL  IN  PERCOLATION,  ETC. 
of  the  drug,  and  thus  is  in  practical  accord  with  the  therapeutic 
trials. 
The  third  division  of  the  table,  consisting  of  two  pairs  of 
columns,  shows  in  the  first  pair  the  weight  of  dry  extract  con- 
tained in  each  successive  portion  of  the  percolate  in  another 
experiment,  and  the  per  centage  value  this  weight  bears  to  the 
whole  of  the  dry  extract  contained  in  a  pint  of  the  finished 
fluid  extract.  This  experiment  was  made  with  a  conical  perco- 
lator, and  is  critically  officinal ;  and  the  next  pair  of  columns  is 
a  precisely  similar  and  parallel  experiment,  except  that  it  was 
made  with  a  cylindrical  percolator,  to  exhibit  the  differences 
arising  from  the  form  of  percolator. 
The  third  portion,  of  two  columns,  is  the  record  of  the  officinal 
experiments  carelessly  and  unskilfully  made  with  a  conical  percola- 
tor, the  results  of  which  were  used  in  the  therapeutic  trials  of  the 
purgative  effect.  That  is,  one-half  of  the  product  of  percola- 
tion was  used  to  determine  the  dry  extract,  and  the  other  half 
for  the  trials  of  medicinal  effect.  The  fourth  pair  of  columns  of 
the  table  is  an  experiment  parallel  with  the  third  pair,  except  that 
a  cylindrical  percolator  was  used,  to  exhibit  the  difference  in 
result. 
The  percolators  used  in  these  experiments  are  so  well  adapted 
in  size  and  form  to  the  management  of  the  officinal  quantities 
that  their  dimensions  may  perhaps  be  usefully  given.  They  are 
made  of  stout  tin  plate  well  and  smoothly  soldered.  The  conical 
one  is  9  inches  across  the  top,  and  the  same  in  the  length  of  the 
side  down  to  the  outlet,  which  outlet  is  f  inch  in  diameter. 
From  this  outlet  projects  downward  a  conical  tube  two  inches 
long,  diminishing  in  size  to  J  inch  or  less  at  the  extremity.  The 
cylindrical  percolator  is  8 J  inches  across  the  top,  2|  inches 
across  the  bottom,  and  11  inches  long.  The  bottom  is  shallow 
cup-shaped,  Avith  a  conical  tube  in  the  centre  an  inch  long,  with 
a  J-  inch  opening  at  the  extremity.  Both  are  fitted  with  close 
covers,  and  are  used  suspended  by  wire  bails  or  handles  attached 
to  opposite  ears  on  the  upper  rim.  When  used  suspended,  they 
are  more  easily  kept  vertical,  and  the  percolation  is  therefore 
more  uniform.  It  is  beside  more  convenient  and  safe  than  when 
set  upon  a  bottle. 
