92    Microscopic  Examination  of  Vegetable  Drugs.    { AFebJruar'yP XT' 
arnica  flowers,  there  are  very  many  cases  in  which  the  microscope 
will  be  found  an  aid  in  judging  of  the  quality.  A  good  deal  may 
be  learned  about  the  quality  of  a  drug  by  taking  into  consideration 
the  microscopic  appearance  of  other  cell  constituents  than  the  active 
ones,  as  of  starch,  calcium  oxalate,  inulin,  chloroplasts,  and  aleurone 
grains.  The  time  of  gathering  the  drug,  the  method  of  drying  it 
and  the  length  of  time  it  has  been  kept  may  all  be  judged  in  many 
instances  by  the  use  of  the  microscope. 
The  spurious  character  of  the  crude  drugs  that  have  been  sold  in 
times  past  is  well  known.  Some  of  the  admixtures  or  substitutes 
can  be  detected  with  the  naked  eye,  but  in  many  instances  a  micro- 
scopic examination  furnishes  the  surest  means  of  determining 
them,  as  in  the  detection  of  ruellia  in  spigelia,  spurious  cascara 
barks,  etc.  I  do  not  desire  to  multiply  examples,  but  may  con- 
clude by  saying  that  one  who  is  accustomed  to  the  examination  of 
drugs  by  means  of  the  microscope  finds  it  an  advantage  to  use  it 
continually. 
CONCLUSIONS. 
When  invited  to  discuss  the  subject  of  this  paper  I  felt  bound  to 
accept  the  invitation,  and  to  do  all  I  could  to  assist  in  future  revisions 
of  the  work,  and  to  make  clear  the  necessity  of  the  consideration  of 
the  progress  in  the  scientific  study  of  vegetable  drugs  and  its  appli- 
cation in  their  examination. 
I  have  pointed  out  what  has  been  done  by  the  other  pharma- 
copoeias and  reviewed  the  difficulties  which  beset  revision  work  in 
this  department  in  our  own  Pharmacopoeia. 
I  have  shown  that  crude  drugs  are  on  the  whole  better  in  quality 
and  less  liable  to  adulteration  than  powdered  drugs,  but  as  commi- 
nuted and  powdered  drugs  are  so  largely  used,  the  pharmacist  must 
be  able  to  determine  them  and  judge  of  their  quality. 
This  being  the  case  the  Pharmacopoeia  should  either  only  give 
definitions  of  vegetable  drugs,  leaving  it  to  be  inferred  that  the 
pharmacist  will  acquaint  himself  with  the  standard  scientific  works 
pertaining  to  them,  and  that  these  constitute  the  standard  the 
Pharmacopoeia  prescribes,  or  it  should  make  the  descriptions  so 
complete  as  to  apply  to  the  various  commercial  forms  of  vegetable 
drugs,  as  I  have  already  stated. 
