ARTIFICIAL  FRUIT  ESSENCES. 
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ARTIFICIAL  FRUIT  ESSENCES. 
BY  FEHL1NG. 
Pine-Apple  Oil  is  a  solution  of  one  part  of  butyric  acid  ether,  in 
eight  or  ten  parts  of  alcohol.  For  the  preparation  of  this  ether, 
pure  butyric  acid  must  be  first  obtained  by  the  fermentation  of 
sugar,  according  to  the  method  of  Bensch. 
"  Dissolve  6  lbs.  of  sugar  and  half  an  ounce  of  tartaric  acid,  in 
26  lbs.  of  boiling  water.  Let  the  solution  stand  for  several  days  ; 
then  add  8  ounces  of  putrid  cheese  broken  up  with  3  lbs.  of  levi- 
gated chalk.  The  mixture  should  be  kept  and  stirred  daily  in  a 
warm  place,  at  the  temperature  of  about  92°  Fahr. 
"  The  liquid  thus  obtained,  is  mixed  with  an  equal  volume  of 
cold  water,  andS  lbs.  of  crystallized  carbonate  of  soda, previously 
dissolved  in  water,  added.  It  is  then  filtered  from  the  precipi- 
tated carbonate  of  lime  ;  the  filtrate  is  to  be  evaporated  down  to 
10  lbs.,  when  5|  lbs.  of  sulphuric  acid,  previously  diluted  with  an 
equal  weight  of  water,  are  to  be  carefully  added.  The  butyric  acid, 
which  separates  on  the  surface  of  the  liquid  as  a  dark-colored  oil,  is 
to  be  removed,  and  the  rest  of  the  liquid  distilled  ;  the  distillate  is 
now  neutralized  with  carbonate  of  soda,  and  the  butyric  acid  sepa- 
rated as  before,  with  sulphuric  acid. 
"  The  whole  of  the  crude  acid  is  to  be  rectified  with  the  addition 
of  an  ounce  of  sulphuric  acid  to  every  pound.  The  distillate  is 
then  saturated  with  fused  chloride  of  calcium,  and  re-distilled. 
The  product  will  be  about  28  ounces  of  pure  butyric  acid." 
One  pound  of  this  acid  is  dissolved  in  one  pound  of  strong  alco- 
hol, and  mixed  with  from  a  quarter  to  half  an  ounce  of  sulphuric 
acid  ;  the  mixture  is  heated  for  some  minutes,  whereby  the  butyric 
ether  separates  as  a  light  stratum.  The  whole  is  mixed  with  half  its 
volume  of  water,  and  the  upper  stratum  then  removed  ;  the  heavy 
fluid  is  distilled,  by  which  more  butyric  ether  is  obtained.  The 
distillate  and  the  removed  oily  liquid  are  shaken  with  a  little  wa- 
ter, the  lighter  portion  of  the  liquid  removed,  which  at  last,  by 
being  shaken  with  water  and  a  little  soda,  is  freed  from  adhering 
acid. 
For  the  preparation  of  the  essence  of  pine-apple,  one  pound  of 
this  ether  is  dissolved  in  8  or  10  pounds  of  alcohol.  20  or  25 
drops  of  this  solution  is  sufficient  to  give,  to  one  pound  of  sugar,  a 
