DETECTION  OF  POPPY  OR  NUT-OIL  IN  OLIVE-OIL.  431 
of  small  shell-fish,  and  adding  to  the  mass  either  a  quantity  of 
urine  in  the  state  of  putrefaction,  or  water  in  which  some  of  the 
same  shell-fish  had  been  allowed  to  putrefy.  The  cloth  soaked 
in  the  liquid  produced  by  these  mixtures  only  developed  the 
beautiful  purple  color  after  long  exposure  to  the  air,  and  probably 
to  heat.  This  mode  of  producing  the  color  so  strikingly  resembles 
that  by  which  the  new  color  of  murexide  is  produced,  that  one  is 
tempted  to  believe  that  the  Tyrian  purple  was  produced  by  that 
substance,  and  that  many  centuries  before  the  beautiful  discovery 
of  Liebig  and  Wohler,  murexide  was  formed  by  the  action  of  am- 
monia, in  the  putrid  matter  employed,  upon  substances  derived 
from  the  uric  acid  which  would  exist  in  the  intestines  of  the  shell- 
fish pounded  up. — Pharmaceutical  Journal,  July,  1854,  from 
Bulletin  de  la  Societe  Industrielle  de  Mulhouse,  No.  123,  p.  242; 
and  Dublin  Journ.  of  Indust.  Progress,  June,  p.  173. 
DETECTION  OF  POPPY  OR  NUT-OIL  IN  OLIVE-OIL. 
By  E.  Marchand. 
In  consequence  of  the  frequent  adulteration  of  olive-oil,  the 
author  had  occasion  to  examine  the  various  methods  of  detecting 
it,  and  has  found  that  the  use  of  sulphuric  acid  gave  satisfactory 
results. 
He  describes  the  process  thus  : — When  4  drops  of  olive,  poppy, 
or  nut-oil  are  placed  separately  upon  a  slab  of  porcelain,  and  2 
drops  of  pure  concentrated  sulphuric  acid  added,  and  mixed  with 
the  oils  by  inclining  the  slab  to  one  side  and  the  other,  the  fol- 
lowing phenomena  are  observed  : — 
Olive-oil  acquires,  at  the  points  of  contact  with  the  acid,  a 
yellow  color  passing  into  orange ;  the  liquid  portion  surrounding 
the  magma  rapidly  becomes  dirty  gray,  and  then  brownish-black, 
while  the  yellow  color  first  produced  by  the  acid  gradually  passes 
into  bright  chestnut-brown.  There  is  never  any  appearance  of 
blue  or  lilac  tints. 
Poppy-oil  acquires,  immediately  at  the  points  of  contact  with 
the  acid,  a  fine  lemon-yellow  color,  which  becomes  rapidly  darker 
at  some  parts.  The  liquid  portion  in  contact  with  the  colored 
portions  never  acquires  the  dirty  gray  color  characteristic  of 
olive-oil.  After  the  reaction  has  continued  for  ten  or  fifteen 
minutes,  there  is  observed,  at  several  points  of  the  liquid  portion 
