Amsijt.?i889arm"}    Reviews  and  Bibliographical  Notices. 
495 
the  different  processes  and  apparatus  for  the  extraction  of  the  active  principles 
of  plants,  and  for  their  concentration,  followed  by  a  double  bibliographical 
table. 
The  importance  of  extracts  as  pharmaceutical  products  has  been  recognized 
at  an  early  date,  and  much  attention  has  always  been  paid  to  their  preparation. 
With  the  gradual  perfection  of  methods  and  apparatus  this  importance  has  not 
been  diminished.  In  the  numerous  essays  devoted  to  this  class  of  medicinal 
agents,  which  have  appeared  from  time  to  time,  we  frequently  meet  with  his- 
torical reviews  of  a  portion  of  the  work  previously  done  in  the  same  direction  ; 
but  even  such  reviews  rarely  trace  the  subject  matter  to  its  original  conception. 
In  the  work  before  us  the  author  aims  at  covering  the  entire  field  of  the  pre- 
paration or  manufacture  of  extracts  from  the  earliest  time  to  the  present,  and 
to  trace,  step  by  step,  the  improvements  which  have  been  introduced  in  the 
processes  as  well  as  in  the  utensils  and  apparatus.  The  whole  subject  is  treated 
from  the  historical  standpoint  alone,  the  first  part  being  devoted  to  the  pro- 
cesses of  evaporation,  followed  by  the  methods  and  apparatus  used  for  the 
exhaustion  of  plants.  Although  it  would  seem  that  the  latter  should  be  con- 
sidered first,  since  exhaustion  must  precede  the  operation  of  concentration,  the 
author  has  chosen  the  order  indicated,  because  much  attention  has  originally 
been  given  to  evaporation  under  various  conditions,  before  any  material 
change  was  made  in  the  methods  of  extraction.  The  third  part  treats  of  the 
employment  of  low  temperatures  (freezing)  in  the  preparation  of  extracts;  and 
the  following  of  the  preservation  of  extracts  in  their  original  condition  and 
quality,  so  as  to  avoid  changes  incidental  to  their  drying  out,  absorption  of 
moisture,  moulding,  fermentation,  etc.  The  last  chapter  is  devoted  to  prepara- 
tions peculiar  to  British  and  American  pharmacy,  namely  to  liquid  extracts, 
fluid  extracts  and  abstracts.  Under  each  chapter  the  chronological  order  is 
preserved  as  much  as  possible  without,  however,  sacrificing  clearness  in  the 
consideration  of  the  gradual,  and  often  times  slow,  perfection  of  the  various 
methods  and  apparatus. 
It  will  be  seen  from  the  foregomg  that  the  book  is  a  unique  one,  and  we  may 
add  that  it  is  a  very  valuable  contribution  to  pharmaceutical  literature,  more 
particularly  to  the  history  of  pharmacy.  The  text  is  illustrated  with  more 
than  one  hundred  wood  cuts  of  implements  and  apparatus,  among  them  a 
number  which  have  been  devised  by  the  author  during  his  prolonged  phar- 
maceutic experience,  or  which  are  in  use  at  the  laboratory  of  Courbevoie. 
A  very  valuable  addition  to  the  work— or  perhaps  more  properly  part  of  it — 
consists  of  bibliographical  tables,  the  one  arranged  alphabetically,  the  other 
chronologically,  of  publications  treating  of  the  different  subjects  to  which  the 
work  is  devoted.  Commencing  with  the  year  1471  and  ending  in  1889,  these 
tables  have  been  prepared  with  great  care,  so  that,  probably,  few  only  of  what 
may  be  considered  the  more  important  essays  have  been  omitted ;  they  con- 
tain, in  each  case,  the  full  title,  name  of  author,  place  and  date  of  publication. 
While  the  literature  of  every  nation  has  been  thus  collated,  essays  from  Great 
Britain  and  the  United  States,  besides  France,  are  particularly  numerous 
during  the  past  thirty  years,  which  is  due  to  the  attention  paid  here  to  perco- 
lation, and  to  the  extensive  use  of  fluid  extracts. 
The  make-up  of  the  work  is  unexceptional ;  but  few  errata  have  escaped  the 
author's  notice,  most  of  them  being  corrected  on  page  xvi.  *The  work  will  be 
