i4  Thymol  and  Carvacrol  Problems.      { A%lZy?mt' 
tion  of  thymol  was  made  by  weighing  the  thymol  recovered  after 
acidification  and  extraction  with  ether  and  evaporation  of  the 
solvent.  In  the  further  operations  of  extraction  the  thymol  recov- 
ered was  weighed  after  the  solvent  had  been  distilled  off  and  thymol 
crystallized  and  allowed  to  stand  in  a  vacuum  desiccator  until  the 
weight  became  constant. 
The  accuracy  of  this  method  was  investigated.  One  gramme  of 
thymol  was  dissolved  in  50  Cc.  of  anhydrous  ether  and  distilled  from 
a  weighing  flask  in  a  hot  water  bath  as  long  as  ether  came  over. 
Then  it  was  transferred  to  a  vacuum  desiccator  over  calcium  chlor- 
ide. The  difference  in  weight  was  attributed  to  volatility  of  thymol 
with  the  vapor  of  the  solvent  under  the  conditions  of  the  experi- 
ment. 
•A  series  of  weighings  on  two  samples  carried  out  over  sixteen 
days  showed  the  following  losses  toward  the  end  of  the  experiment: 
Sample  1,000  g. 
Loss  per  Loss  per 
I.  day.  II.  day. 
Gms.           Gms.           Qms.  Gms. 
Weighed    30.6863    27.5524   
Feb.    4   30.83+    27.68   
Feb.    6    30.7066    27.5652   
Feb.  14    30.6946    27.5524   
Feb.  18    30.6692  0.0062  27.5266  0.0064 
Feb.  19    30.6660  0.0032  27.5256  0.0010 
Feb.  20    30.6676  gain  27.5253  0.0003 
Total  recovery   97-97  p.  c.  97-33  P-  c. 
The  ether  distillate  was  tested  for  thymol  by  Flueckiger's  test 
and  10  Cc.  gave  a  positive  reaction  but  the  chloroform  layer  retained 
no  pink  of  violet  color  indicating  only  slight  quantities  of  thymol. 
In  this  series  it  was  noticed  that  the  thymol  remained  fluid 
during  the  entire  16  days  and  only  solidified  after  inoculation. 
Another  series  was  run  starting  with  moist  ether  that  was  standing 
over  a  layer  of  water  in  order  to  duplicate  more  closely  the  condi- 
tions of  extraction  of  solutions  where  the  ether  is  recovered  in  the 
moist  condition.  One  gramme  of  thymol  was  dissolved  in  50  Cc. 
and  the  ether  distilled  off  and  weighings  made.  After  standing  over 
night  in  the  open  air,  the  residue  was  seeded  and  weighings  con- 
tinued. 
