^^Vay^mr-}      On  Preservation  of  certain  Oils,  201 
ON  PRESERVATION  OF  THE  OILS  OF  ORANGE  AND  LEMON. 
To'the  Editor: 
Showing  a  friend,  a  few  days  ago,  some  oil  of  lemon,  which  I  had 
kept  fresh  and  fragrant  for  over  one  year,  he  urged  me  to  communi- 
cate the  process  to  the  Journal  for  publication. 
The  operation  is  as  follows  :  To  every  pound  of  oil  1  oz.  of  alco- 
hol is  to  be  added,  and  well  mixed  ;  then  1  oz.  of  water  is  put  with  it^ 
which  again  withdraws  the  alcohol  from  the  oil,  and  collects  at  the 
bottom  of  the  bottle  as  dilute  alcohol. 
The  oil  I  have  treated  in  this  manner  was  in  a  large  quart  bottle, 
hardly  more  than  half  full,  and  is  to  day  as  nice  as  when  first  pur- 
chased. 
In  trying  to  explain  to  myself  the  theory  of  this  action,  the  oil  wa& 
closely  observed,  and  a  resinous  film  was  found  floating  on  the  sur- 
face of  the  dilute  alcohol.  Whether  the  separation  of  this  resinous 
film  preserves  the  fragrance  of  the  oil,  or  whether  the  presence  of 
water  has  so  good  a  result,  I  have  not  yet  determined,  but  am  certain 
that  the  general  theory  of  deterioration  by  contact  with  air  does  not 
hold  good  in  this  case.  Precisely  the  same  effect  was  observed  with 
oil  of  orange,  and  it  was  an  agreeable  surprise  to  find  the  experiment 
work  so  well  with  both  oils. 
I  would  like  to  add,  that  the  resinous  film  observed  seemed  to  be 
in  much  larger  quantity  in  the  oil  of  orange,  and  for  that  reason  I 
think  this  is  the  true  cause  of  its  spoiling  more  rapidly  than  the  oil 
of  lemon. 
I  send  you  a  sample  of  each  of  the  oils. 
Very  respectfully,  Carl  Fruh. 
Philadelphia,  April  Qth,  1871. 
Remarks  hy  the  Editor.  The  fact  that  a  small  amount  of  alcohol 
added  to  the  volatile  oils  of  the  aurantiacese  preserves  them,  is  known 
to  many  wholesale  druggists,  as  well  as  pharmacists,  and  for 
many  years  we  have  preserved  these  volatile  oils  by  the  addition  of 
1  oz.  of  alcohol  to  a  pound  of  the  oil.  The  subsequent  addition  of 
a  small  quantity  of  water  probably  does  not  entirely  remove  the  alco- 
hol dissolved  in  the  volatile  oil.  We  would  suggest  to  the  author  to 
continue  his  experiments  and  ascertain  how  much  alcohol  remains 
with  the  oil.  It  is  very  probable  that  the  removal  of  foreign  resinous 
and  other  matters  has  the  effect  of  retarding  oxidation  by  the  atmo- 
sphere. 
