34 
Notes  on  Essential  Oils. 
(  A.m.  Jour.  Piiarm . 
1     January,  1908. 
by  volume,  and  dilute  alcohol  (Fortyndet  Vinaand,  Spiritus  dilutus) 
with  68  to  70  per  cent,  by  volume. 
The  individual  oils  may  now  follow: — 
Anise  Oil.  (Aetheroleum  anisi), — At  low  temperatures,  a  white 
crystalline  mass,  which  commences  to  melt  at  150,  and  at  about 
20°  represents  a  colorless  or  faintly  yellowish,  strongly  refractive 
liquid;  dlso  0-980  to  0*990*;  soluble  in  1-5  to  5  volumes  alcohol. 
Clove  Oil  {Aether oleum  caryophilli). — In  the  fresh  state  bright  yel- 
low, in  the  course  of  time  acquiring  a  brownish  color;  d15Q  1-045  to 
1-070;  soluble  in  2  volumes  dilute  alcohol. 
Fennel  Oil  (Aetheroleum  foenieuli). — Colorless  or  faintly  yellow; 
d150  0-965  to  0-975 ;  soluble  in  an  equal  volume  alcohol;  when 
cooled  to  about  +  5  0 ,  it  should  solidify  to  a  crystalline  mass.2 
Lavender  Oil  (Aetheroleum  lavandulae). — Light  yellow  or  greenish 
yellow;  d15C  0.885  to  0-895  5  soluble  in  every  proportion  in  alcohol, 
and  in  3  volumes  dilute  alcohol. 
Lemon  Oil  [Aetheroleum  citri). — Light  yellow  ;  d15C  0-859  to  0861;3 
with  5  volumes  alcohol  it  forms  a  not  quite  clear  solution  ;  lemon 
oil  must  not  show  a  strong  acid  reaction. 
Menthol  (Mentholum). — Colorless,  brittle,  needle-shaped  crystals, 
not  moist.  M.  p.  430  4;  b.  p.  2120  5  ;  only  very  slightly  soluble  in 
water ;  very  readily  soluble  in  alcohol,  ether,  chloroform,  and  fatty 
oils.  When  heated  in  an  open  dish  on  a  water-bath,  menthol  should 
evaporate  completely. 
Oil  of  Parsley  Seed  (Aetherohum  petroselini). — Viscid,  yellowish 
to  brownish  yellow  ;  d153  1-050  to  1  100  ;  soluble  in  an  equal  volume 
alcohol. 
Peppermint  Oil  (Aetheroleum  menthae  piperitae).  Colorless,  yel- 
lowish or  greenish  yellow;  d15°  0-900  to  09206;  at  20°  soluble  in 
•  :  
1  It  is  recommended  to  determine  the  specific  gravity  at  20°,  as  anise  oil 
sometimes  solidifies  already  spontaneously  at  150  ;  the  above  limits  of  value 
also  apply  to  200. 
2  Solidification  must  sometimes  be  started  by  inoculation  with  a  small 
quantity  of  solid  anethol,  as  under  certain  conditions  fennel  oil  ma3^  be  cooled 
much  below  its  solidification  point  without  actually  solidifying. 
3  It  would  have  been  better  to  have  given  0  857  as  lower  limit  of  value. 
4  The  m.  p.  of  menthol,  taken  exactly,  lies  between  43-5  and  44-5°. 
5  Menthol  boils  about  2170  if  the  mercury  thread  of  the  thermometer  is 
entirely  placed  in  the  steam. 
6  According  to  the  specific  gravity,  both  English  and  American  oils  are 
allowed. 
