22  Early  History  of  Percolation.       { A  janJu°aury 
tions  to  pharmacy  and  demonstrating  its  usefulness  there  to  the 
Boullays.  This  evidence  of  contemporary  opinion  is  important, 
particularly  as  it  is  voiced  by  a  man  who  had  made  an  extensive 
investigation  of  the  whole  problem.  Guillermond  also  confirms  the 
Boullays  conclusion  of  the  uselessness  of  the  column  of  Real.  It  is 
interesting  to  note  that  all  of  the  many  new  forms  of  percolating 
apparatus  which  utilize  this  method  for  exerting  pressure  on  the 
contents  of  the  percolator  have  been  uniformly  rejected  by 
pharmacists. 
When  Guillermond's  thesis  was  reprinted  in  the  Annalen  der 
Pharmacie  (without  the  acknowledgments  which  literary  courtesy 
demands)  Geiger22  appended  to  it  a  critical  commentary  in  which 
he  exhibits  much  mental  confusion,  being  unable  to  distinguish  the 
totally  different  nature  of  the  principles  involved  in  the  processes 
of  Real  and  Boullay;  in  addition, — we  are  almost  led  to  say  with 
racial  characteristic, — he  claims  that  the  knowledge  of  the  process 
was  already  widespread  in  Germany  and  adds,  "and,  apparently, 
in  France."  Of  these  statements  he  offers  no  proof  whatsoever, 
and,  however  well  the  process  may  have  been  thought  to  have  been 
known  in  Germany  before  the  Boullays  published  their  investiga- 
tions, an  examination  of  the  literature  will  show  that  such  knowl- 
edge was  derived  wholly  from  French  sources  and  none  of  it  was 
•original.  What  may  have  been  done  outside  of  the  literature  Ave 
"have  no  means,  at  this  date,  of  knowing.  A  consideration  of  what 
.the  Germans  have  done  with  percolation  since  that  time  will,  how- 
ever, leave  any  American,  who  is  familiar  with  the  detailed  and 
extensive  investigations  of  American  pharmacists,  very  much  in 
'doubt  as  to  whether  the  Germans  have  ever  thoroughly  understood 
.  die  principles  which  underlie  percolation  or  not.  In  this  connec- 
tion a  paper  by  Vielguth  and  Nentwich,23  "On  the  most  correct 
methods  for  preparing  extracts,"  may  be  consulted. 
The  new  process  must  have  attracted  widespread  attention  in 
France.  Dausse,  aine,  invented  a  percolating  apparatus  to  which  he 
added  a  water  bath  and  still.24  Dausse  investigated  the  extraction 
of  eighty  drugs,  a  labor  of  no  small  moment. 
22  Annalen  der  Pharmacie,  vol.  15,  p.  95,  1835. 
23  Wittstein's  Vierteljahresschrift,  y.  1858,  pp.  321,  481;  this  Journal,  vol. 
3i,  P-  233,  1859. 
24  Abs.  in  Jour,  de  Pharm.,  vol.  21,  p.  369,  1835. 
