ANovJeTbefhi89^-}      Oils  of  Winter  green  and  Birch.  561 
that  I  am  not  endeavoring  to  cast  a  reflection  on  any  of  Dr.  Power's 
results,  but  that  I  simply  desire  to  have  the  facts  of  the  case  known. 
SUMMARY  OF  THE  MOST  IMPORTANT  CONCLUSIONS  REGARDING  THE  COMPO- 
SITION OF  THE  OILS  OF  WINTERGREEN  AND  BIRCH. 
Trimble  and  Schroeter,  Power,  in  1889.  Power  and  Kleber,  in 
in  1889.  1895. 
"We  find,  in  addition      "The    natural    oil   of  "Oil    of  wintergreen 
to  methyl  salicylate,  in  wintergreen    consists    of  (Gaultheria)  contains 
both  oils  a  hydrocarbon  methyl    salicylate,    with  about   99   per   cent,  of 
of  the  formula  C15H24  *  *  small   amounts  (0*3  per  methyl  salicylate,  togeth- 
The  amount  of  the  hydro-  cent,  or  less)  of  a  terpene.  er  with  a  small  amount 
carbon  is  from  o  "3  to  o  "447  The  latter  is  a  slightly  of  a  paraffin,  which  is  pro- 
per cent.,  and  it  becomes  yellowish,  somewhat  vis-  bably  triacontan,  C30H62, 
solid  on  standing  a  short  cid  liquid,  having  an  odor,  an  aldehyde  or  ketone, 
time,  or  on  cooling.  It  is  as  described  by  Cahours,  an  apparently  secondary 
probably  made  up  of  a  resembling  that  of  black  alcohol,  C^H160,  and  an 
solid  and  a  liquid  por-  pepper,  a  specific  gravity  ester  C14H2402." 
tion."                               of  approximately  0*940, 
and  does  not  solidify  or 
separate  any  solid  sub- 
stance at  a  temperature 
of— io°C." 
"The  oils  are  physi- 
cally and  chemically 
identical,  the  only  differ- 
ence detected  being  in 
the  melting  points  of  the 
hydrocarbons.  That  from 
wintergreen  melted  at 
from  io°  to  i5°C,  and 
that  from  birch  at  180  C." 
"The  oil  of  birch,  wl 
pure,  consists  simply 
methyl  salicylate." 
en  ' '  Oil  of  sweet  birch  (Be- 
of  tula),  in  its  unrectified 
state,  contains  about  99*8 
per  cent,  of  methyl  sali- 
cylate, together  with  a 
very  small  amount  of  the 
above-mentioned  paraffin, 
C30H62,  an  aldehyde  or 
ketone,  and  the  ester 
CuH2i02)  but  does  not 
contain  the  alcohol 
C3H160,  which  is  found  in 
gaultheria  oil." 
"We  find  in  both  oils  "  In  the  natural  oils  of  "Neither  the  oil  of 
small  quantities  of  ben-  wintergreen  and  birch  gaultheria  nor  the  oil  of 
zoic  acid  and  ethyl  alco-  examined  by  me,  no  trace  sweet  birch  contains  any 
hoi."  of  benzoic  acid  could  be  trace  of  benzoic  acid  or 
detected,  nor  has  suffi-  its  esters,  nor  do  they 
cient  evidence  as  yet  been  contain  any  terpene  or 
afforded  to  establish  be-  sesquiterpene." 
yond  doubt  the  presence 
of  ethyl  alcohol  in  these 
oils." 
There  are  other  results  summarized  in  all  three  contributions, 
but  they  are  not  especially  matters  of  dispute.  In  the  absence  of 
any  observations  of  my  own  on  the  optical  properties  of  these  oils, 
I  am  willing,  for  the  present,  to  accept  those  of  Power  and  Kleber, 
who  state  that  oil  of  sweet  birch  is  optically  inactive,  and  that  oil  of 
