542 
Oil  of  Monarda  Fistulosa. 
(  Am.  Jour.  Pharui. 
I     October,  1896. 
the  months  June,  July,  August  and  September  ;  also  statements  with 
reference  to  the  parts  of  plants  used,  specific  gravity  and  rotatory 
power  of  oil,  as  well  as  the  results  of  a  crude  phenol  estimation. 
Estimation  of  Carvacrol. — The  results  of  the  carvacrol  determi- 
nations recorded  in  Table  I  were  obtained  by  shaking  25  c.c.  of  the 
oil  with  75  c.c.  of  a  10  per  cent,  solution  of  sodium  hydroxide. 
The  amount  of  oil  not  dissolved  by  the  soda  solution  was  read  off 
and  the  difference  was  calculated  as  carvacrol. 
It  is  known,  however,  that  strong  solutions  of  caustic  alkali  par- 
ticularly not  only  dissolved  phenols,  but  other  substances,  hydro- 
carbons, alcohols,  etc.,  as  well.  Oil  No.  9,  which,  when  shaken  but 
once  with  a  10  per  cent,  soda  solution,  showed  70  per  cent,  of 
carvacrol;  when  shaken  four  times  with  a  5  per  cent,  solution  of 
soda  solution,  showed  only  54-8  per  cent,  carvacrol.  Duplicate 
tests  were  made.  The  following  table  indicates  the  results  of 
the  repeated  action  of  the  soda  solution  in  the  oil  on  duplicate 
tests : 
I. 
ir. 
Per  Cent. 
Per  Cent. 
3o-8 
524 
55'2 
.........  54*4 
55'2 
It  thus  becomes  apparent  that  the  amounts  in  Table  I  have  only 
a  relative  value. 
Phenol  determinations  of  the  dark  oil  obtained  from  plants  col- 
lected at  Picnic  Point  were  also  made.  In  one  estimation  the  oil, 
however,  was  diluted  with  an  equal  volume  of  petroleum  ether. 
With  a  10  per  cent,  soda  solution  the  undiluted  oil  showed  65-2  per 
cent,  and  65  6  per  cent.,  respectively.  Diluted  with  petroleum 
ether,  the  oil  showed,  with  10  per  cent,  soda  solution,  60  4  per  cent, 
and  6o-8  per  cent.,  respectively;  100  c.c.  of  undiluted  oil,  shaken 
first  with  300  c.c,  then  with  100  c.c,  and  lastly  with  50  c.c  of  5 
per  cent,  soda  solution,  gave,  respectively,  in  duplicate  tests,  the 
following  results  : 
I. 
II. 
Per  Cent. 
Per  Cent. 
42-5 
  52-5 
53*5 
  56-5 
57  "5 
