54  Pharmacognosy  and  the  US.P.  {^JuZyfwt 
paper  Tschirch  1  writes :  "  For  when  the  isolated  substances  are 
tested  pharmacologically,  it  becomes  evident  that  their  action  does 
not  correspond  with  that  of  the  drug  itself — for  the  latter  scarcely 
ever  contains  a  single  active  constituent  but  frequently  a  remarkable 
mixture  of  substances  that  are  often  antagonistic  in  their  effects. 
I  will  refer  only  to  rhubarb,  which,  in  addition  to  laxative  anthra- 
glucosides,  contains  astringent  tannoglucosides,  and  owes  its  thera- 
peutical use  to  the  simultaneous  occurrence  of  these  two  antagonistic 
groups  of  substances.  Although,  unable  to  free  ourselves  from 
the  views  of  Galen,  drugs  are  still  called  '  simples,'  they  are  in 
reality  far  from  simple ;  indeed  they  are  extraordinarily  complex 
substances." 
Again,  Turner  in  a  recent  paper  2  has  called  attention  to  some 
of  the  newer  views  in  regard  to>  the  components  of  drugs  on  which 
medicinal  activity  depends  and  to' a  tendency  to  abandon  the  idea 
that  the  principles  separated  by  assay  truly  represent  the  value  of 
the  drug.  He  says :  "  Boulanger-Dausse  in  Bulletin  des  Sciences 
Pharm.,  No.  I,  1908,  pays  particular  attention  to  this  question  and 
comes  to  the  following  conclusions : 
"  The  endeavor  to  isolate  the  '  alkaloid '  to  which  scientific  phar- 
macy paid  such  vivid  attention  for  nearly  one  hundred  years  begins 
to  lose  its  practical  significance.  The  chemistry  of  colloids  partly 
takes  its  place  and  the  chemist  and  pharmacologist  pay  more  and 
more  attention  to  certain  complex  ingredients  of  drugs,  or,  as  they 
are  usually  called,  '  extractives  '  of  drugs. 
"  A  diligent  and  successful  investigation  of  certain  drugs  showed 
conclusively  that  the  active  principles  isolated  from  them  in  the 
course  of  one  hundred  years  and  studied  both  chemically  and  phar- 
macologically did  not  satisfy  the  requirements  which  the  physician 
had  right  to  put  to  them.  Cinchona,  digitalis,  ergot,  rhubarb,  buck- 
thorn, cascara  sagrada,  kola,  opium  and  mix  vomica  are  the  best 
examples  illustrating  what  was  said  before. 
"  Many  prominent  pharmaceutic  chemists  and,  lately,  especially 
Kunz-Krause,  recognized  this  in  proper  time  and  showed  that  in 
many  cases  the  production  of  chemically  pure  active  principles  of 
drugs  can  no  longer  be  the  ultimate  purpose  of  pharmacy.  It  is 
more  proper  to  expect  that  in  the  future  pharmaceutical  science  will 
direct  its  work  toward  production  of  chemically  unchanged  colloidal 
1 Pharm.  Jour.  (London),  83,  420,  October,  1909. 
2  Am.  Jour.  Pharm.,  81,  125,  March,  1909. 
