Am.  Jour.  Pharm. 
Jan.,  1891. 
Notes  on  Essential  Oils. 
47 
finest  products  of  the  lavender  districts  of  South  France.  As  will  be  seen  from 
the  appended  table,  the  sp.  gr.  varied  considerably,  and  gave  evidence  of  a 
relationship  to  the  solubility,  those  of  lower  gravity  being  more  soluble.  The 
optical  polarizing  power  is  also  subject  to  considerable  variation,  and  does  not 
appear  to  be  very  suitable  for  the  detection  of  adulteration. 
Sp.gr. 
at  150. 
Rotation 
Solubility  in 
Source  and  Age. 
in  a 
70  per  cent. 
100  mm.  col. 
alcohol. 
— 
A 
0-897 
-  4°  15' 
—  D  0 
insoluble 
TJ 
±> 
O  090 
<  < 
c 
0-893 
—  8°  22/ 
D 
0-894 
—  8°  16' 
u 
(  insoluble  at  160, 
E 
Gard,  1889,  
0-891 
—  90  20/ 
<  but  dissolved  on 
[_  warming  to  200. 
F 
I<                       tt  <( 
0-887 
-  4°  48/ 
soluble 
G 
0-887 
—  70  8/ 
H 
tt                 it  ft 
o-888 
-  6°  51/ 
<  » 
I 
Gard,  1889,  
o-888 
—  6°  20/ 
« s 
K 
0-885 
—  6°  48' 
L 
Alpes  maritimes,  1889,  ...... 
0889 
-  6°  58' 
tt 
M 
0.885 
—  40  26/ 
tt 
N 
Herault,  1889,  
0-887 
-  6°  56' 
ft 
In  order  to  discover  the  constituent,  which  was  the  cause  of  the  insolubility, 
25  kilos  A  was  fractionated  with  steam.  Lavender  oil,  boiling  at  a  higher  tem- 
perature than  turpentine,  the  latter,  if  present,  would  appear  in  the  first  frac- 
tion and  be  detected  by  its  slight  solubility  in  70  per  cent,  alcohol.  But  the 
four  first  fractions  readily  dissolved,  and  only  the  last  and  smallest  refused  to 
dissolve.    The  presence  of  turpentine  was,  therefore,  negatived. 
The  difference  in  behavior  with  the  solvent  ought  to  be  ascribed  to  the  fact 
that  in  the  case  of  insoluble  oils  the  distillation  is  pushed  further  than  in  that 
of  the  soluble,  i.  e.,  that  constituents  with  higher  boiling  points  and  difficultly 
soluble  are  carried  over  toward  the  end  of  the  process.  It  is  probable  that  the 
soluble  oils  are  subjected  to  rectification  in  which  the  least  volatile  fractions 
are  kept  back.  These  experiments  prove  that  an  oil  may  be  unadulterated  and 
not  stand  the  test.  Messrs.  Schimmel  state  that  the  test  is  unreliable  in 
detecting  adulteration,  as  the  soluble  oils  G,  H  and  I  dissolved  perfectly  clear 
with  70  per  cent,  alcohol  at  160  .even  after  the  addition  of  15  to  20  per  cent,  oil 
of  turpentine.  The  age  of  the  turpentine  used  proved  to  have  some  influence 
on  the  solubility.  Of  an  old,  somewhat  resinified  oil  of  turpentine,  20  per 
cent,  could  be  added,  whilst  of  a  freshly  rectified  specimen  only  15  per  cent, 
were  admissible. 
the  70  per  cent,  alcohol,  and  1  part  of  spike  oil  in  2  parts.  Insolubility  indi- 
cating adulteration  with  turpentine,  camphor  oil,  castor  oil,  etc.  The  test  is 
stated  to  be  relied  on  by  the  large  houses  in  Grasse,  who  all  buy  these  oils  from 
small  distillers  in  the  mountains.  G.  M.  B. 
