/ 
20  Early  History  of  Percolation.       { A™aJu°aurry;  ^J™- 
ported.  As  a  sign  of  their  carefullness  and  observation  it  may  be 
remarked  that  they  noticed  a  sensible  difference  in  the  extracts 
yielded  by  these  different  fractions  !  This  is  highly  interesting  in 
view  of  the  later  work  of  Squibb.13  The  Boullays  recognized  the 
fact  that  the  residual  liquor  in  the  marc  left  by  the  old  process  is 
of  the  same  composition  as  that  pressed  out.  They  again  insist  upon 
the  importance  of  the  principle  of  displacement  and  name  the  process 
the  "  method  of  displacement." 
"  Que  le  deplacement  immediat  et  continu,  applique  a  de  f  aibles 
quantites  de  liqueurs,  devra  etre  generalement  adopte  dans  ce  genre 
d'operations ;  car  les  premiers  produits  sont  excessivement  concen- 
tres, et  la  force  de  ceux  qui  suivent  decroit  dans  une  proportion 
extremement  rapide." 
Pelouse14  used  percolation  in  his  work  on  nut  galls ;  "  Le  tannin 
extrait  de  la  noix  de  galle  par  Tether  hydrate  a  l'aide  de  la  method 
de  deplacement  est  incolore  et  sane  odeur,  etc."  He  gives  no  one 
credit  for  developing  the  process. 
During  the  next  year  Robiquet15  inserted  in  his  account  of 
meconic  acid  a  description  of  his  percolator: 
"  Je  profiterai  de  Foccasion  pour  faire  connaitre  plus  generale- 
ment 1'appereil  dont  je  me  sers  depuis  plusiers  annees,  et  dont  il  a 
deja  ete  fait  mention  dans  le  memoir  que  j'ai  publie  conj  ointment 
avec  M.  Boutron,  sur  l'huile  d'amandes  ameres." 
This  is  the  same  apparatus  described  in  1831.  Robiquet  had 
taken  no  notice  of  the  work  of  the  Boullays  up  to  this  time. 
Another  memoir  by  the  Boullays  appeared  in  1835.16  In  this 
they  extend  the  process  to  new  drugs  and  quote  the  results  obtained 
by  several  pharmacists  in  the  use  of  displacement.  They  now  assert 
priority  over  Robiquet,  resenting  the  statement  of  Guibourt17  who 
had  given  their  apparatus  the  name  of  the  "  displacement  funnel  of 
Robiquet,"  and  those  of  Bonastre18  who  stated: 
"J'ai  essaye  de  mettre  en  usage  le  procede  de  deplacement  in- 
dique  par  nos  honorables  colleges  Robiquet  et  Boutron  Charlard,  et 
en  dernier  lieu  par  M.  Boullay." 
13  This  Journal,  vol.  39,  p.  402,  1867. 
14  Annates  de  Chimie  et  de  Physique,  December,  1833 ;  Jour,  de  Pharm., 
vol.  20,  p.  356,  1834. 
15  Jour,  de  Pharm.,  vol.  20,  p.  79,  1834. 
1GJour.  de  Pharm.,  vol.  21,  p.  1,  1835. 
17  "  Traite  de  Pharmacie,"  Tome  II,  p.  39. 
18  Jour,  de  Pharm.,  vol.  20,  p.  281,  1834. 
