•^ovem&T'J       Valuation  of  Drugs  and  Foods.  543 
pulv.  sarsaparillse  comp.,  and  others  for  making  fluid  extracts 
and  other  pharmacopceial  preparations.  I  recently  met  with 
a  rather  interesting  case,  which  is  worthy  of  mentioning  here. 
In  examining  some  compound  licorice  powder,  which  had  been 
in  a  container  on  a  shelf  for  about  nine  months,  I  found  that 
there  was  an  uneven  distribution  of  the  different  substances 
that  entered  into  it.  I  have  reason  to  believe  that  they  were  origi- 
nally well  mixed,  but  that,  upon  standing  in  a  building  in  a  large  city 
where  traffic  of  teams,  etc.,  in  the  streets  was  continuous,  causing 
vibrations  or  jarring,  there  was  a  fractional  precipitation  of  the  dif- 
ferent substances  entering  into  the  powder,  those  which  were  heavier 
or  smaller  in  size  manifesting  a  tendency  to  form  a  lower  strata,  and 
those  tissues  that  were  more  fibrous  and  lighter  remaining  nearer 
the  surface.  This  serves  to  indicate  the  importance  of  examining 
the  compound  powders  that  may  be  purchased  and  also  of  shaking 
up  the  powders  in  the  containers  beiore  using  them. 
(2)  The  use  of  the  microscope,  where  micro-chemical  reactions  are 
to  be  employed,  will,  no  doubt,  be  somewhat  limited  in  the  imme- 
diate future,  owing  to  certain  difficulties  in  technique  in  the  work. 
There  are  a  number  of  drugs,  however,  in  which  important  data 
may  be  obtained  by  this  means,  as  nux  vomica,  strophanthus,  hy- 
drastis,  spigelia,  crocus,  etc. 
{a)  When  nux  vomica  is  sectioned  and  treated  with  a  sulphu- 
ric acid  solution  containing  K2Cr07  or  cerium  hydroxide,  a  rose- 
colored  reaction  appears  in  the  endosperm  cells  which  contain  the 
strychnine.  The  reaction  is  rather  a  slow  one,  owing  to  the  thick- 
ness of  the  cell  walls  of  the  endosperm. 
(b)  Strophanthus  Seeds. — Sections  of  the  seed  are  put  into  con- 
centrated H2S04  (C.  P.).  Those  containing  strophanthin  give  a 
green  color,  apparently  in  the  endosperm  layer.  It  must  be  said, 
however,  that  in  seeds  in  which  some  of  the  sugar  compounds 
are  present,  there  results,  with  the  albuminoids  and  nitrogen- 
containing  compounds  and  the  H2S04,  a  rose  or  red  or  reddish- 
brown  color.  These  color  reactions  sometimes  obscure  the  green  of 
the  strophanthin. 
(c)  Hydrastis. — Sections  of  the  rhizome,  when  put  into  concen- 
trated H2S04  (C.  P.),  give  in  the  course  of  a  lew  minutes  a  number 
of  needle-shaped  crystals  of  the  alkaloids.  These  increase  in 
number  and  size  as  the  walls  dissolve,  and  in  the  course  of  half  an 
hour  the  mount  is  filled  with  yellow  microscopic  crystals. 
