894 
Tests  for  Methyl  Salicylate. 
\  Am.  Jour.  Pharni. 
I      December,  1920. 
It  is  not  a  difficult  matter  to  devise  new  tests  which  appear 
to  give  distinctive  results  working  with  a  single  set  of  authentic 
samples.  I  have  discovered  several  such  tests  in  the  short  time 
with 'which  I  worked  in  the  preparation  of  this  article.  It  occurred 
to  me  that  inasmuch  as  both  gaultheria  and  birch  oils  are  made  from 
drugs  which  contain  more  or  less  woody  cellular  tissue,  that  condi- 
tions would  be  favorable  for  the  production  of  furfuraldehyde  in 
the  distillation  of  these  oils,  and  it  will  be  noted  that  an  aldehyde 
has  been  reported  in  gaultheria  oil,  although  its  identity  was  not  es- 
tablished. The  application  of  several  of  the  better  known  tests 
for  furfuraldehyde,  notably  the  aniline  acetate  test,  such  as  is  used 
for  detecting  invert  sugar  in  honey,  were  applied  and,  as  was  ex- 
pected, positive  results  were  obtained.  With  this  test,  for  instance, 
a  specimen  of  authentic  gaultheria  oil  gave  an  immediate  intense 
red  color;  birch  oil  gave  a  pronounced  red  color,  more  slow  in 
its  appearance,  and  methyl  salicylate  gave  a  negligible  reaction. 
Other  tests  for  furfuraldehyde,  as,  for  example,  the  Badouin  test 
for  sesame  oil,  in  which  hydrochloric  acid  containing  one  per  cent, 
of  sugar  is  the  reagent,  also  showed  differences  in  the  intensity  ot 
the  reaction,  but  when  applied  to  mixtures  the  test  becomes  prac- 
tically valueless,  for  reasons  explained  in  connection  with  several 
of  the  foregoing  tests.  It  would  be  easy,  also,  to  defeat  the  objects 
of  such  a  test  by  the  addition  of  a  small  amount  of  furfuraldehyde 
to  the  methyl  salicylate  used  for  adulteration  purposes. 
At  times  during  the  past  five  or  six  years  it  has  been  stated  in 
print  (Schimmel's  Report,  April,  1914,  p.  99)  or  the  rumor  has 
circulated  throughout  the  essential  oil  trade  that  the  U.  S.  Depart- 
ment of  Agriculture  chemists  are  in  possession  of  a  test  which  en- 
ables the  detection  of  adulteration  of  gaultheria  or  birch  oils  with 
methyl  salicylate  with  certainty.  Such  test  has  never  been  pub- 
lished and  if  it  exists  it  is  probably  based  upon  one  of  the  previously 
published  tests  or  upon  some  such  reaction  as  the  one  I  have,  de- 
scribed for  furfuraldehyde,  for  instances  might  be  found  of  adul- 
teration so  gross,  say  90  per  cent,  of  methyl  salicylate  to  10 
per  cent,  of  the  genuine  oil,  that  a  difference  in  intensity  could  be 
noted.  It  is  more  likely  that  the  majority  of  the  prosecutions  which 
have  been  brought  for  adulterations  of  this  kind  have  been  based 
upon  inspectors'  actual  knowledge  of  admixture. 
I  have  at  various  times  been  presented  with  so-called  authentic 
samples  of  oils  of  gaultheria  and  oil  of  birch.    Three  of  these  sam- 
