Am jfc^7h6arm- }  Powdered  Drugs  under  the  Microscope. 
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Several  other  species  of  Manihot  are  said  to  furnish  a  part  of  the 
tapioca  in  the  trade.  Their  starch-grains  are  much  like  those  just 
described,  and,  in  the  present  state  of  our  information,  it  is  not  practi- 
cable to  distinguish  them. 
Tapioca  is  said  to  be  adulterated  with  potato,  sago  and  wheat-starch. 
It  is,  itself,  used  as  an  adulterant  of  arrowroot. 
3.   SAGO  (Fig.  3). 
The  starch  from  the  stem  of  several  species  of  palm-trees,  gene- 
rally Sagus  Rumphii. 
The  grains  are  ovate  or  oval,  with  the  margins  sometimes  slighlty 
concave.  The  rings  are  evident,  and 
there  is  a  round  or  star-shaped  nucleus 
nearest  the  larger  end.  Many  of  the 
grains  are  singularly  compound,  consisting 
of  a  large  grain,  with  one  or  more  much 
smaller  ones  forming  protuberances  on  it. 
In  commercial  specimens,  the  grainlets  of 
the  compound  grain  are  usually  separated 
from  each  other,  and  show  only  the  flat- 
tened surfaces  where  they  were  in  contact.  The  length  of  the  grains 
is  from  jtt.  to  24//.,  usually  above  14^. 
Granulated  sago  is  made  into  small,  round  masses  by  being  passed 
through  a  sieve  and  subjected  to  heat.  The  masses  are  brownish  in 
color.    The  starch-grains  are  but  little  altered  by  heat. 
Pearl  sago  is  in  larger,  white,  spherical  masses,  which  in  the  course 
of  preparation  have  been  subjected  to  considerable  heat,  and  afterwards 
bleached.  The  grains  of  starch  in  this  case  are  swollen  and  distorted, 
and  the  nucleus  is  bulging. 
The  principal  adulteration  of  sago  is  by  means  of  potato  starch. 
From  it  a  false  sago  is  made,  which  resembles  the  real  article  very 
closely.  The  microscope  will  readily  show  the  difference  between 
them.    Sago  is  employed  as  an  adulterant  of  several  other  starches. 
4.   ARROWROOT,  OR  MARANTA  (Fig.  4). 
The  starch  from  the  root- stock  of  Maranta  arundinacea  and,  per- 
haps, other  species  of  the  same  genus. 
It  is  a  powder,  with  small  scattered,  irregular  masses,  of  a  dead- 
Fig.  3.  Sago  starch. 
