Ans/P°tur' i92iarm* }  Determination  of  Camphor.  601 
From  these  determinations  all  of  the  oils  would  appear  to  be 
commercially  pure,  the  cottonseed  oil  gave  a  high  saponification 
value,  whilst  the  refractive  index  of  the  olive  oil  is  slightly  below 
normal. 
Standard  solutions  of  camphor  were  then  prepared,  eighty  grams 
of  the  various  oils  were  weighed  into  glass  stoppered  bottles  and  ex- 
actly twenty  grams  of  camphor  added,  giving  solutions  20  per  cent, 
by  weight,  as  required  by  the  British  and  United  States  Pharmaco- 
pceia.  After  the  solutions  were  uniformly  mixed,  five  gram  samples 
of  each  were  weighed,  into  five  centimeter  diameter  platinum  dishes 
and  placed  in  a  Freas  oven,  previously  regulated  to  1200  C.  At  the 
same  time  four  gram  samples  of  each  oil  were  weighed  into  similar 
dishes  and  heated  in  the  same  oven.  At  the  end  of  two  hours  all  the 
samples  were  removed  from  the  oven,  desiccated  for  twenty  min- 
utes, and  weighed.  This  process  was  repeated  for  a  third  and  fourth 
hour.  The  weights  at  the  end  of  the  fourth  hour  were  very  little 
different  from  those  at  the  end  of  the  third,  except  in  the  case  of 
cottonseed  oil,  which  was  heated  for  a  fifth  hour. 
The  refractive  indicies,  saponification  values  and  iodine  num- 
bers of  the  oils  after  being  heated  both  with  and  without  camphor, 
for  five  hours  in  the  case  of  cottonseed,  and  four  hours  in  the  other 
cases,  were  then  determined,  with  the  following  results : 
TABLE  11. 
REFRACTIVE  INDICIES    (ABBE)    AT  40°  C. 
Heating  Heating 
Oil  Before  Heating       with  Camphor,  without  Camphor 
Cottonseed  .  .     1.4648  (58.3)    1.4680  (63.2)  1.4667  (61.2) 
Peanut  ......     1.4639(56.9)    1.4660(60.2)  1.4654(59.2) 
01ive    1.4622  (54.3)    1. 463 1  (55.7)  1.4626  (55.0) 
Sesame    14652  (58.9)    1.4687  (64.3)  1.4679  (63.1) 
The  equivalent  Butyro  refractometer  readings  are  included  in 
brackets.  The  effect  of  heating  the  oils  has  in  every  case  been  to 
raise  quite  appreciably  the  refractive  index,2  a  greater  effect  being 
produced  on  the  oil  when  containing  dissolved  camphor.  These 
values  may  afford  some  information  for  the  identification,  by  means 
of  the  refractometer,  of  these  oils  after  heating  to  volatilize  cam- 
phor. 
2  Compare  Utz  (Chemical  Technology  &  Analysis  of  Oils,  Fats  &  Waxes, 
P-  343,  V.I). 
