Am  M™y?i903arm*}       Some  Notes  on  Essential  Oils.  223 
safrol  and  the  ethyl  ether  of  hydroquinone.  While  the  odor  and 
other  physical  properties  depend  largely,  if  not  entirely,  on  the  con. 
tained  anethol,  it  will  be  readily  appreciated  that  on  closer  examina- 
tion the  two  oils  would  present  marked  differences.  To  overcome 
any  possible  misunderstanding  between  the  two  oils,  the  German 
and  the  Swedish  Pharmacopoeias  direct  that  under  oil  of  anise 
only  the  oxygenated  portion  of  the  oil,  the  anethol,  be  dispensed  or 
used  in  medicinal  preparations.  Anethol,  according  to  Schimmel  & 
Co.,  should  congeal  at  from  21°  to  220  C;  the  melting  point  accord- 
ing to  the  same  authority  is  somewhat  higher,  being  from  22-5°  to 
2270  C. 
The  German  as  well  as  the  Swedish  Pharmacopoeia  gives  the 
congealing  point  of  anethol  as  from  20°  to  21 0  C,  the  specific 
gravity  from  0*984  to  0  986,  and  the  boiling  point  from  23 2°  to 
2340  C. 
In  view  of  the  fact  that  anethol  is  commercially  available,  at  a 
price  little  above  that  of  good  oil  of  anise  seed,  it  would  appear  as 
though  the  Pharmacopceial  Revision  Committee  would  be  justified 
in  restricting  the  title  of  oil  ot  anise  to  the  oxygenated  portion,  or 
anethol. 
Oil  of  Caraway. — This  is  another  of  the  essential  oils  that  dif- 
fer in  composition  and  physical  properties.  Kremers,  in  comment- 
ing on  oil  of  caraway  (Phar.  Rev.,  1 902,  p.  467),  asks:  "  What  should 
be  recognized  as  oil  of  caraway  by  the  U.S. P.,  the  crude  oil  the  rec- 
tified oil,  the  twice  rectified  oil  or  carvone  ?  All  of  them  are  said 
to  be  articles  of  commerce,  and  all  of  them  differ  in  their  chemical 
constituents  and  physical  properties. 
Here  again  the  German  and  Swedish  Pharmacopoeias  have  taken 
what  would  appear  to  be  the  most  rational  course  and,  as  in  the 
case  of  oil  of  anise,  direct  that  the  oxygenated  portion  alone  be 
recognized  as  oil  of  caraway.  The  Swedish  Pharmacopoeia  gives 
the  specific  gravity  of  carvone  as  being  from  0-963  to  0-966  at  1 50  C, 
and  the  boiling  point  from  2290  to  2300  C. 
In  contrast  to  these  figures,  having  a  rather  limited  range,  it  may 
be  mentioned  that  the  limits  of  specific  gravity,  according  to  the 
official  Pharmacopoeias,  varies  from  0-883,  the  minimum  of  the  Por- 
tuguese, to  0-960,  the  maximum  of  the  Russian  Pharmacopoeia.  The 
boiling  point,  according  to  the  Portuguese  Pharmacopoeia,  may  vary 
from  1900  to  245 0  C. 
