558  Enzymes  and  Their  Importance.  {^j£Z?&t 
not  yet  answered.  The  human  organism  itself  forms  so  many 
enzymes  that  it  is  extremely  probable  that  those  ingested  are  de- 
stroyed or  assimilated.  Zymase,  for  instance,  is  destroyed  by  the 
proteolytic  ferment  of  the  pancreatic  gland.  At  present  there  are  a 
number  of  "  sterilised  "  drugs  on  the  market  as  well  as  phamaceutical 
products  made  from  them — digitalis,  for  instance:  but  it  must  be 
remembered  that  the  pharmacological  action  of  these  "  sterilised  " 
drugs  must  be  further  studied,  as  our  present  knowledge  is  based 
chiefly  on  the  use  of  non-sterilised  drugs.  A  case  illustrating  the 
action  of  enzymes  is  afforded  by  gum  acacia :  mucilage  of  acacia 
undergoes  considerable  changes  when  mixed  with  other  substances, 
especially  readily  oxidised  substances,  and  for  this  reason  the  Swiss 
Pharmacopoeia  requires  it  to  be  heated — i.e.,  to  destroy  the  enzyme. 
On  the  other  hand,  several  enzymes  display  a  useful  action.  This  is 
apparent  in  the  processes  to  which  such  drugs  as  tea,  cocoa,  coffee, 
tobacco,  vanilla,  and  tamarinds  are  subjected  to  improve  them.  "With 
several  drugs  the  perfume  is  only  apparent  after  enzymatic  processes 
have  been  at  work  during  drying;  thus  fresh  orris-root  is  almost 
odorless. 
All  these  processes  have  as  yet  been  but  little  studied,  and  it  is  only 
when  we  are  thoroughly  acquainted  with  the  cause,  conditions,  and 
course  of  them  that  we  shall  be  able  to  regulate  and  improve  them, 
and  here  a  wide  field  of  research  opens  up  for  pharmacognosy.  Our 
aim  is  not  only  to  eliminate  the  deleterious  actions  of  enzymes,  but 
to  subject  the  actions  to  the  service  of  man  and  to  make  them  useful 
for  drugs,  such  as  has  been  done  in  the  preparation  of  foodstuffs — 
e.g.,  in  brewing  and  in  making  wine,  cheese,  bread — where  the  process 
of  "  fermentation  "  is  due  to  enzymatic  action.  W "hen  we  have 
learned  to  utilise  the  enzymes  formed  by  higher  plants,  such  as  is 
now  the  case  with  myrosin  in  the  preparation  of  oil  of  mustard  and 
of  emulsin  in  the  splitting  up  of  almond-amygdalin.  the  number  of 
useful  enzymatic  actions  will  be  considerably  enlarged,  and.  to  quote 
Goethe,  from  wonder  we  shall  proceed  to  consideration,  and  from 
consideration  to  examination.  We  are  led  to  this  thesis  by  the 
philosophy  of  pharmacognosy,  and  by  experiment  guided  by  the 
process  of  thought.  As  Houston  Stewart  Chamberlain  remarks: 
"  La  science  sans  philosophic  est  un  simple  bureau  d'enregistrement." 
