a.  Jour.  Pharni.  \ 
August,  1559.  ) 
Oils  of  Wintergreen  and  Birch.  399 
cific  gravities  and  boiling  points  shows  a  remarkable  similarity  among 
the  samples  in  this  respect. 
Sample, 
Boiling  Point,  C. 
Specific  Gravity  at  15°  C. 
I. 
216° 
1-1838 
II. 
217° 
1-1840 
III. 
216° 
1-1845 
IV. 
Birch  
217° 
1-1840 
Since  these  data  have  shown  considerable  variation  at  the  hands  of 
different  investigators,  we  used  every  precaution  to  arrive  at  correct 
results,  and  from  them  one  cannot  but  conclude  that  these  figures  could 
be  of  no  practical  value  in  distinguishing  the  oils. 
Chemical  Composition. — Two  methods  of  saponifying  these  oils  have 
been  proposed,  one  by  boiling  for  some  hours  with  excess  of  concen- 
trated potassium  hydrate  solution,  which  will  be  designated  the  hot 
process,  and  the  other,  proposed  by  Professor  J.  U.  Lloyd,1  by  pouring 
the  oil,  slowly,  with  constant  stirring,  into  a  concentrated  solution  of 
potassium  hydrate  heated  to  82°  C. 
It  was  noticed  by  Procter  that  when  the  oil  of  wintergreen  was 
dissolved  in  potassium  hydrate  solution  in  the  cold  it  formed  a  solid 
mass,  from  which  the  oil  separated  unchanged  on  the  addition  of 
hydrochloric  acid.  We  found  no  separation  of  the  oil  after  heating  to 
82°  C.  as  directed  by  Lloyd,  although  several  trials  were  made  with 
both  methods,  and  we  finally  adopted  a  modification  of  Lloyd's 
formula,  using  about  one-half  the  potassium  hydrate  recommended  in 
it,  attaching  the  flask  to  an  upright  condenser  and  heating  on  a  water- 
bath  for  one-half  hour. 
By  this  method  we  saponified  about  800  grams  of  each  oil.  Both 
oils  after  saponification  possessed  a  characteristic  fragrant  odor,  entirely 
distinct  from  that  of  the  oil.  The  clear  solutions  were  agitated  with 
purified  petroleum  ether,  b.  p.  25°  to  45°  C,  and  the  process  repeated 
with  three  portions  on  each.  The  aqueous  solutions,  after  final  sepa- 
ration from  the  petroleum  ether,  were  almost  free  from  odor,  and  were 
set  aside  for  treatment  with  acid. 
THE  HYDEOCAEBOXS. 
The  different  portions  of  petroleum  ether  were  mixed,  keeping  those 
from  the  two  oils  separate,  the  solvent  in  part  recovered  by  distillation, 
1  TJ.  S.  Dispensatory,  16th  edition,  p.  100. 
