AF4br°uUary!Sm' }    Microscopic  Examination  of  Vegetable  Drugs.  91 
another  in  the  arrangement  or  grouping  into  tissues.  As  already 
pointed  out  the  latter  method  is  followed  in  the  German  pharmaco- 
poeia. 
THE  USE  OF  THE  MICROSCOPE  IN  THE    EXAMINATION  OF  COMMINUTED 
AND  POWDERED  DRUGS. 
The  microscope  furnishes  the  surest  means  ol  determining  the 
identity  of  a  powdered  vegetable  drug  at  our  command,  and  is 
also  useful  in  determining  the  quality  of  powders,  as  in  strophan- 
tus, hydrastis,  ginger,  black  pepper,  amylum,  etc.  The  microscope 
also  furnishes  the  most  reliable  means  of  detecting  and  determining 
adulterants  in  powdered  drugs.  It  is  furthermore  useful  in 
detecting  the  presence  of  worm-eaten  drugs  or  powders  of  certain 
classes  of  drugs  which  have  been  exhausted  in  whole  or  in  part. 
When  the  active  principles  of  starch-containing  drugs  have  been 
removed  this  is  indicated  by  an  alteration  in  the  starch  grains,  as 
in  belladonna,  calumba,  ipecac,  rhubarb,  licorice,  etc.  Exhausted 
oleo-resinous  drugs  are  readily  detected  by  the  use  of  chloral  as  a 
mounting  medium,  which  has  the  effect  of  bringing  out  the  oil  and 
resin  cells  in  the  genuine  drug.  There  are  also  a  number  of  micro- 
chemical  tests  which  apply  to  individual  drugs  that  are  coming  into 
use.  The  presence  of  added  lime  in  cochineal  and  other  drugs 
may  be  detected  by  the  use  of  25  per  cent,  sulphuric  acid,  as  a 
mounting  medium  which  causes  a  separation  of  crystals  of  calcium 
sulphate. 
I  have  had  a  great  many  occasions  to  use  the  microscope  not  only 
in  the  detection  of  adulterants  but  also  in  determining  drugs  which 
were  mislabeled.  On  one  occasion  a  jobber  sent  out  comminuted 
belladonna  root  for  inula,  and  discovered  later  that  the  bin  in  which 
the  drug  was  kept  was  wrongly  labeled.  On  another  occasion  when 
I  ordered  genuine  "  almond  meal  "  and  a  mixture  marketed  as 
almond  meal,  I  found  the  labels  were  interchanged,  apparently  not 
wholly  accidentally,  but  on  account  of  the  finer  appearance  of  the 
spurious  article. 
The  Value  of  the  Microscope  in  the  Examination  of  Crude 
Drugs. 
In  addition  to  the  aid  furnished  in  identifying  crude  drugs  by  a 
microscopic  examination  as    in   digitalis,  solanaceous  leaves  and 
