Am.  Jour.  Pharm.\ 
March.  1891.  I 
Sesame  Oil  in   Olive  Oil. 
applied  myself  to  the  task  of  obtaining  a  more  satisfactory  test  for 
the  latter.  I  have  been  successful  in  findifig  one,  which,  although 
it  cannot  rank  with  the  silver  test  for  cotton  seed  oil,  still  enables 
one  to  detect  with  rapidity  and  ease  5  per  cent,  of  adulteration, 
while  I  per  cent,  can  be  detected  by  exercising  a  little  care  in  the 
manipulation.  I  found  that  the  acetic  acid  extract  from  sesame  oil, 
which  I  was  examining  for  another  purpose,  mentioned  in  my  next 
note,  turned  blue  or  bluish-purple  when  boiled  with  HC1,  in  which 
a  few  grains  of  pyrogallol  had  been  dissolved.  The  same  experi- 
ment was  tried  with  sesame  oil  itself,  using  equal  parts  of  the  pyro- 
gallol solution  with  the  oil,  with  the  result  that  the  pyrogallol  solu- 
tion turned  purple.  I  treated  olive  oil  in  a  similar  manner  and 
found  it  to  give  only  a  faint  yellow  coloration.  Almond,  rape  and 
ground  nut  oils  gave  no  color,  while  sunflower  oil  turned  the  solu- 
tion a  very  faint  blue,  and  cotton  seed  oil  imparted  a  very  light  red. 
It  now  occurred  to  me  that  this  behavior  of  sesame  oil  with  HC1 
solution  of  pyrogallol  might  be  utilized  for  its  detection  in  olive  oil. 
Accordingly  solutions  of  sesame  oil  in  olive  oil  of  various  percentage 
were  prepared  and  the  test  applied.  The  following  are  the  results 
obtained  upon  treating  olive,  sesame  and  other  oils  with  hydro- 
chloric acid,  solution  of  pyrogallol  and  boiling  : 
Pure  Olive  :  faint  yellow. 
Sesame  :  deep  purple. 
20  p.  c.  Sesame  :  purple. 
10  p.  c.  Sesame  :  purple. 
5  p.  c.  Sesame  :  faint  purple. 
1  p.  c.  Sesame :  very  faint  purple. 
Almond  :  colorless. 
Ground  Nut  :  colorless. 
Cotton  Seed  :  very  faint  red. 
Sunflower  :  faint  olive. 
Rape  :  colorless. 
Oleic  Acid  :  faint  red. 
I  obtained  the  best  results  by  applying  the  test  as  follows,  viz  : 
Prepare  a  solution  of  pyrogallol  in  pure  hydrochloric  acid  (3ss.  to 
Measure  half  an  ounce  of  this  solution  into  a  wide-mouthed  test- 
tube  provided  with  a  cork,  and  add  half  an  ounce  (an  ounce  if  the 
proportion  of  sesame  oil  be  small)  of  the  oil  to  be  tested.  Shake 
vigorously  and  then  set  aside  for  about  a  minute  to  allow  the  oil 
and  acid  to  separate.  Draw  off  the  supernatant  liquid  by  means  of 
a  pipette,  and  boil  the  hydrochloric  acid  solution  for  about  five 
minutes,  when,  if  sesame  oil  be  present,  the  color  of  the  solution 
will  have  changed  to  purple.  The  color  does  not  appear  at  once, 
but  develops  on  boiling  for  a  short  time.  When  viewed  by  trans- 
mitted light  the  color  is  wine  red  to  purple,  and  by  reflected  light  it 
