Amjune;x87h7arm  }  The  Rotatory  Power  of  Volatile  Oils.  309 
Pure  beechwood-tar  creasote  consists  chiefly  of  guaiacol,  with  a 
little  creasol,  and  should  have  the  following  qualities  : 
It  is  a  colorless,  or  nearly  colorless,  oily  fluid,  of  1*08  sp.  grav.,  dis- 
tilling, unaltered,  between  2000  and  2500  C.  After  exposure  to  light 
for  several  months,  even  in  open  glasses, Jt  should  only  become  light- 
yellow  (wine  color),  and  not  red.  Creasote  which  turns  red  contains 
foreign  bodies,  and  is  not  fit  for  medicinal  use.  It  must  be  entirely 
soluble  in  caustic  lye,  and  on  the  addition  of  water  carbohydrogen  oils 
should  not  separate.  Most  of  these  are  very  difficult  to  remove,  and 
possess  a  disagreeable  odor.  It  should  answer  to  the  above-mentioned 
tests,  and  be  soluble  in  80  parts  of  cold  water.  Boiling  water  takes 
up  a  larger  quantity,  but  separates  it  again  after  several  days.  It 
takes  up  50  per  cent,  of  its  volume  of  glycerin — sp.  gravity  1*250. 
An  adulteration  of  creasote  wrth  carbolic  acid  can  be  approximately 
determined  by  fractional  distillation,  and  especially  by  combining  with 
a  saturated  alcoholic  potash  lye,  and  recrystallizing  from  ether.  The 
carbolic  acid  enters  the  mother-liquor,  from  which  it  may  be  separated 
by  an  acid,  and  its  presence  proved  by  another  distillation. 
PRACTICAL  NOTES  ON  THE  ROTATORY  POWER  OF 
THE  VOLATILE  OILS. 
By  F.  A.  Fluckiger.1 
If  we  say  that  the  solid  or  fluid  (at  the  ordinary  temperature)  ether- 
eal oils  are  the  bearers  of  the  odor  and  mostly  also  of  the  taste  of  the 
respective  plants,  this  sentence  will  pretty  well  express  the  general  idea 
of  the  nature  of  the  ethereal  oils  and  stearoptens.  Though  little 
accurate,  it  is  still  easier  to  dispute  this  definition  than  to  give  a  more 
satisfactory  one.  Some  volatile  oils,  which  are  liquid  at  I7°C,  have 
•very  little  odor,  as  for  instance  the  oil  of  the  seeds  of  Nigella  sativa, 
and  amongst  the  solid  parts  of  the  ethereal  oils  many  are  entirely  odor- 
less, like  the  crystallizable  parts  of  rose-  and  bergamot-oil.  The  odor 
is  therefore  not  an  indispensable  necessary  quality  of  these  bodies, 
neither  is  the  distillability,  as  many  of  the  oils  are  not  distillable  to  the 
last  drop. 
If  we  must  acknowledge  that  no  quality  can  be  mentioned  as  being 
1  Abstract  from  a  paper  published  in  "  Archiv  der  Pharmacie,"  March,  translated 
by  Edward  Lamhofer. 
