^"■jiZ'^s^ys""'}  ^ote  on  Scammony,  29 
ing  wheat  starch,  wood  ashes,  earth,  gum  arable  or  tragacanth,  pounded 
scammony  roots,  etc. 
The  starch  granules  peculiar  to  the  scammony  root  are  shown  in 
this  diagram  ;  they  are,  for  the  most  part,  compound,  composed  of  two, 
three,  and  sometimes  more  granules.  In  shape  the  single  granules  re- 
semble those  of  Tacca,  muUer-shaped,  with  dihedral  base,  and  the 
hilum  approximates  to  that  seen  in  the  starch  of  orris-root.  With 
polarized  light  the  arms  of  the  black  cross  run  down  in  the  direction 
of  those  lines  marked  on  the  grains.  Occasionally  a  lenticular  grain 
is  met  with,  but  the  hilum  or  markings  about  the  hilum  serve  to  dis- 
tinguish it  from  that  of  wheat  starch,  to  which  it  otherwise  bears  a 
close  resemblance. 
The  starch  grains  from  the  scammony  root  vary  very  much  in  size 
about  the  centre  of  the  root,  where  the  texture  is  loose  ;  some  granules 
will  be  found  very  large,  at  the  same  time  in  company  with  these  will 
be  found  a  good  many  of  very  variable  size. 
From  an  examination  of  a  variety  of  samples  of  virgin  scammony 
from  different  sources,  I  may  state  as  a  result,  that  the  lump  was  in  every 
instance  free  from  the  starch  of  scammony-root  or  any  other  starch, 
and  that  every  sample  of  powdered  virgin  scammony  contained  more  or 
less  of  the  scammony  starch,  and  some  of  them  a  little  wheat  starch 
in  addition.  A  few  also  contained  particles  of  the  tissue  peculiar  to 
the  root  with  the  starch  grains  still  in  it,  and  I  would  observe  that  the 
