Am.  Jour.  Ptiartxi. t 
January,  1908.  / 
Notes  on  Essential  Oils. 
35 
3  to  5  volumes  dilute  alcohol ;  when  more  solvent  is  added,  at  most 
a  slight  cloudiness  may  occur. 
Rose  Oil (Aetheroleum  rosae).  Light  yellow,  sometimes  greenish 
yellow  and  fairly  viscid.  At  a  temperature  below  18  to  21°,  pointed 
or  laminated  crystals  separate  out  from  the  oil,  and  if  cooled  further, 
the  oil  solidifies  completely;  d20°  0-855  to  0-870;  only  partly  soluble 
in  alcohol. 
Rosemary  Oil  (Aether oleum  rosmarini).  Colorless,  or  yellowish  to 
greenish  yellow;  d15~  0900  to  0-920;  soluble  in  0-5  and  more  vo- 
lume alcohol. 
Sandal  Oil,  East  Indian  (Aetheroleum  santali). — Fairly  viscid  ; 
light  yellow  to  yellow;  d150  0-975  to  0  99° 1  •  at  20°  soluble  in  5 
volumes  dilute  alcohol,  the  solution  must  also  remain  clear  if  more 
alcohol  is  added. 
Thyme  Oil  (Aetheroleum  thymi). — Colorless  or  yellowish,  subse- 
quently red-yellow  ;  d15o  0-900  to  0  930 ;  soluble  in  half  its  volume 
alcohol. 
Thymol  (Jhymolum). — Colorless,  transparent  crystals;  m.  p.  51  to 
5202;  b.  p.  228  to  2300  3;  completely  volatile  at  the  temperature  of 
the  water-bath.  Molten  thymol  floats  on  water,  crystallized  thymol 
sinks  in  it.  Soluble  in  1100  volume  water,  very  readily  in  alcohol 
ether,  and  chloroform,  also  in  2  volume  caustic  soda  liquor  (con- 
taining 10  per  cent.  NaOH).  Identity  reactions  and  test  for  carbolic 
acid. 
Turpentine  Oil,  purified  (Aetheroleum  terebinthinae.)  Colorless ; 
d15=  o-86o  to  0-870;  soluble  in  about  10  volume  alcohol.  If  the  oil 
is  shaken  with  an  equal  volume  water,  the  latter  must  not  take  an 
acid  reaction;  10  cc.  oil,  when  evaporated  on  a  water-bath,  may 
leave  behind  only  a  trace  of  solid  residue. 
1  The  upper  limit  of  value  of  the  specific  gravity  is  given  too  low  ;  it  should 
be  C985. 
2  The  melting  point  lies  between  50*5  and  51-5°. 
3  Thymol  boils  between  233  and  2340,  if  the  mercury  thread  of  the  thermo- 
meter is  placed  entirely  in  the  steam. 
