Am'iay?i908arm*}  Oil  °f  Bergamot.  205 
work  of  Burgess  and  Page  (Report,  April-May,  1905)  as  follows: 
"  In  spite  of  the  statement  made  by  the  authors  that  they  had  to 
deal  with  an  unsophisticated  bergamot  oil  (the  purity  of  the  oil  is 
by  no  means  proved  by  the  constants  mentioned  by  the  authors), 
we  beg  to  doubt  as  yet  the  presence  of  octylene,  pinene  and  cam. 
phene  in  pure  bergamot  oil,  as  in  the  course  of  this  winter  we  were 
more  than  once  able  to  convince  ourselves  of  the  large  dimensions 
which  the  adulteration  of  bergamot  has  acquired." 
The  constituent  which  has  received  most  attention  is  linalyl 
acetate,  which,  although  modified  by  other  bodies,  gives  the  char- 
acteristic  odor  to  bergamot  oil.  Linalyl  acetate  is  present  in  the  pure 
oil  to  the  extent  of  about  32  to  40  per  cent. ;  this  refers  only  to  the 
pressed  oil,  as  that  obtained  by  steam  distillation  from  the  pressed 
residue  contains  a  low  percentage  of  ester,  due  to  decomposition. 
The  following  table  shows  the  low  ester  content  of  distilled  oils 
(Schimmel,  Report,  April,  1893): 
Solubility 
Specific  Rotation  in  1*5  to  2  Ester 
Gravity  100  m.m.     Vols.  8  Per  Cent  Per  Cent, 
15°  C  Alcohol. 
1.  From  residue  after  pressing,    '873  — {—  r  1 0  2c/       Soluble  12*4 
2.  From  residue  after  pressing,    "873  4~4°  Soluble  i2-o 
3.  Oil  of  40  per  cent,  ester, 
rectified,  "871  +20°  40'       Soluble  22*0 
The  color  of  bergamot  oil  is  due  to  the  presence  of  chlorophyll, 
although  copper  may  be  present  in  some  cases.  We  have  examined 
twenty-three  samples  of  oil  and  have  not  been  able  to  find  copper. 
The  following  test  was  used  :  10  c.  c.  of  oil  are  shaken  with  3  drops 
of  concentrated  hydrochloric  acid  for  30  seconds,  5  c.  c.  of  water  are 
added  and  the  mixture  again  shaken.  After  the  mixture  has  separated, 
I  drop  of  5  per  cent,  potassium  ferrocyanide  solution  is  added  to  the 
aqueous  layer.  If  copper  be  present,  a  reddish-brown  coloration  or 
precipitate  is  produced.  Three  samples  of  oil  which  gave  no  reac- 
tion with  the  above  test  were  allowed  to  stand  over  copper  foil  for 
two  days  at  the  ordinary  temperature.  After  this  treatment,  they 
all  gave  strong  reactions,  one  of  the  samples  yielding  a  considerable 
precipitate  of  copper  ferrocyanide. 
The  following  results  were  obtained  in  the  examination  of  twenty- 
three  samples  of  bergamot  oil : 
