278  Microscopical  Examination  of  PowdersJ^i^lJ^™*' 
some  sulphates,  the  insoluble  portion  of  the  "  black  "  being  fine 
sand. 
It  is  evident  that  without  the  most  careful  examination,  the  pres- 
ence of  these  mixtures  in  ground  spices  might  often  escape  notice. 
The  starch  granules  are  usually  so  much  altered  in  the  process  of 
baking  as  to  render  their  identification  almost  impossible. 
As  pure  ground  pepper,  for  instance,  yields : 
Moisture,  8-10 
Ash,  2-5 
Starch,   .  .  .   .  34-43 
Total  reducing  sugar  equiv.,  42-55 
It  is  obvious  that  in  case  of  admixture  with  this  material,  the 
determination  of  any  or  all  of  those  constituents  would  be  of  no 
value,  and  it  is  probable  that  the  only  reliable  fesults  would  be 
obtained  from  estimating  the  amount  of  piperine  and  resin,  which  is 
quite  constant. 
Some  points  of  similarity  to  other  spices  might  be  mentioned  to 
show  how  admirably  these  mixtures  are  adapted  to  their  purpose  : 
but  the  object  of  this  paper  is  simply  to  call  attention  to  what  is 
believed  to  be  the  latest  development  of  inventive  genius  in  this 
direction. 
MICROSCOPICAL  EXAMINATION  OF  POWDERS. 
By  Hans  M.  Wilder. 
Powders. —  Considering  the  number  of  histological  elements  of 
varying  specific  gravity  which  constitute  a  drug  when  powdered, 
and  considering  the  small  amount  of  powder  actually  present  in  a 
"  mount  "  (seldom  more  than  one-half  to  one  grain,  generally  less),, 
it  will  be  evident  that  a  single  slide  rarely,  if  ever,,  fully  represents 
the  drug.  It  will  be  necessary,  therefore,  first  to  insure  the  thor- 
ough mixing  of  the  powder  (either  by  shaking  of  the  container  or 
by  triturating  a  portion  in  a  mortar),  and,  secondly,  to  make  about  a 
dozen  slides,  the  examination  of  which  will  bear  out  the  above  state- 
ment. Once,  on  examining  powdered  Alexandria  senna,  the  writer 
made  twenty  slides  before  he  found  the  middle  layer  of  the  fruit 
pulp,  for  an  illustration  of  which  see  Proceedings  A.  Ph.  A.,  1882,. 
p.  240,  E. 
