306 
Notes  on  Essential  Oils. 
Am.  Jour  Pharm. 
June,  1893. 
again  come  into  the  Chinese  market,  and  it  is  stated  to  be  absolutely 
pure.  This  deficiency  is  accounted  for  by  the  statement  that  young 
and  imperfectly  ripened  material  always  yields  such  oil.  On  exami- 
nation, Messrs.  Schimmel  found  that  the  oil  was  not  to  be  distin- 
guished by  its  external  appearance  and  characters  from  oil  of  the  best 
quality.  It  did  not  contain  rosin,  fat,  oil,  petroleum,  or  any  of  the 
coarser  adulterants.  This  oil  has  been  rejected  by  the  Hong  Kong 
merchants,  but  some  of  it  has  found  its  way  to  India  and  places 
where  low  price  is  the  chief  attraction  and  there  is  but  little  appre- 
ciation of  quality.  The  explanation  given  by  the  Chinese  of  its 
inferior  character  cannot  be  summarily  rejected,  since  it  is  possible 
that  young  leaves  may  contain  a  considerable  proportion  of  the  acetic 
ester  of  cinnamyl  (C9H9.OAc),  and  that  cinnamic  aldehyde  may  be 
formed  from  that  by  oxidation  during  the  growth  of  the  plant.  But 
it  is  more  probable  that  this  inferior  oil  is  derived  from  other  parts 
of  the  plant,  or  from  another  species  of  the  genus  of  Cinnamomum. 
Messrs.  Schimmel  remark  that  the  previous  history  of  this  subject 
furnishes  no  inducement  to  believe  the  statements  made  by  the 
Chinese,  and  they  reserve  their  opinion  until  they  shall  have 
examined  the  raw  material  from  which  the  inferior  oil  is  obtained. 
Meanwhile,  they  recommend  that  the  determination  of  cinnamic 
aldehyde  should  be  made  the  test  of  quality  in  purchasing  the  oil, 
and  they  state  that  the  oil  imported  since  last  October  has  been 
found  to  contain  at  least  85  per  cent,  and  sometimes  as  much  as  94 
per  cent,  of  cinnamic  aldehyde. 
Bergamot  Oil. — For  many  years  the  examination  of  this  oil  has 
been  limited  to  the  determination  of  its  physical  characters,  and  it 
is  only  within  the  past  year  that  the  acetic  ester  of  linalool  has  been 
recognized  as  its  most  important  constituent.  This  fact  pointed  to 
a  means  of  determining  the  quality  of  the  oil,  as  the  ester  is  the 
odorous  constituent.  By  a  saponification  method,  described  under 
the  head  of  "  Lavender  Oil,"  the  normal  amount  of  ester  has  been 
found  to  be  about  40  per  cent.,  and  the  test  may  be  relied  upon  for 
ascertaining  the  quality  of  bergamot  oil.  The  chief  adulterants  are 
turpentine,  orange  and  lemon  oils.  All  three  reduce  the  solubility 
of  bergamot  oil  in  dilute  alcohol,  as  well  as  the  specific  gravity,  and, 
of  course,  the  amount  of  ester.  The  presence  of  orange  oil  is  also 
indicated  by  its  high  optical  rotation.  In  the  examination  of  ber- 
gamot oil,  it  is  necessary  in  the  first  place  to  determine  the  specific 
