Am'juOiy!*i908.arm  }    Examination  of  Commercial  Ginger.  313 
Ground  or  Powdered  Ginger. — The  color  of  powdered  ginger  varies 
from  pale  yellow  to  light  or  dark  brown.  The  odor  is  strongly  aro- 
matic and  characteristic,  and  the  taste  is  very  pungent.  In  the 
making  of  the  tincture  of  ginger,  the  U.  S.  Pharmacopoeia  directs 
that  the  ginger  shall  be  in  the  form  of  a  moderately  fine  powder, 
that  is,  the  particles  composing  the  powder  shall  be  about  0-5  mm. 
in  diameter.  An  examination  of  the  commercial  powdered  ginger 
shows  that  the  particles  exclusive  of  starch  grains  vary  from  O-i  to 
06  mm.  in  diameter.  Buchwald9  call  attention  to  the  fact  that  when 
powdered  ginger  is  dropped  upon  the  surface  of  water  the  particles 
rapidly  separate  from  one  another  and  then  sink  in  the  liquid.  This 
behavior  of  the  ginger  particles  is  all  the  more  marked  when  it  is 
compared  with  that  of  ether-extracted  ginger,  starch  or  lycopodium. 
When  powdered  ginger  is  treated  with  pure  sulphuric  acid,  a  reddish- 
brown  color  is  at  first  produced,  which  rapidly  changes  to  dark 
brown  and  finally  to  purplish-brown. 
In  the  microscopic  examination  of  the  powders  {Fig.  5)  it  is  neces- 
sary to  use  several  reagents.  After  making  a  preliminary  examina- 
tion of  the  material  mounted  in  water,  portions  of  the  powders  may 
then  be  mounted  in  one  of  the  fixed  oils,  as  olive  or  almond.  While 
this  medium  brings  out  all  of  the  elements  of  the  powder,  it  is  espe- 
cially useful  in  the  study  of  the  starch  grains.  For  this  purpose  it  is 
necessary  to  use  a  small  quantity  of  material,  not  more  than  a  milli- 
gram to  two  or  three  drops  of  oil.  The  entire  field  should  be  exam- 
ined carefully  and  the  size  and  shape  of  the  grains  noted.  If  the 
preparation  be  heated  at  a  temperature  of  6o°  C.  for  10  to  15  min- 
utes, the  polarizing  effects  of  the  grains  become  more  pronounced 
[Fig.  j).  Inasmuch  as  there  are  no  lignified  cells  in  ginger,  phloro- 
glucin  is  another  important  reagent  in  the  examination  of  the  powder, 
serving  to.  detect  any  of  the  usual  adulterants  which  contain  lignified 
cells,  as  wheat  middlings  or  capsicum.  The  sclerenchymatous 
fibers  may  be  isolated  by  the  use  of  Schulze's  macerating  fluid. 
When  the  cells  are  separated,  the  material  is  mounted  in  alcoholic 
methylene  blue  and  glycerin  is  added  (Fig.  4).  Sulphuric  acid  is 
not  only  useful  for  determining  the  presence  of  ether-exhausted 
ginger  and  distinguishing  the  oil  and  resin  cells,  and  the  presence 
or  absence  of  cork,  but  is  especially  useful  in  detecting  the  fungus 
of  moldy  ginger,  the  hyphae  and  spores  being  both  brought  out 
with  this  reagent. 
