14 
Gum  from  the  Oil  Tree. 
/Am.  Jour.  Pharm„ 
I     January,  1898. 
200°  C.j  clearly  showing  that  decomposition  was  taking  place  in  the 
hot  substance  in  the  flask. 
The  heat  was  continued  and  the  thermometer  was  allowed  to  re- 
main in  the  distilling  flask  until  the  temperature  of  the  distillate 
rose  to  3600  C.  Up  to  this  point  only  a  small  amount  of  the  liquid 
had  distilled  over,  although  the  atmospheric  pressure  in  the  distill- 
ing flask  was  the  same  as  at  the  beginning  of  the  operation. 
After  the  thermometer  had  been  removed,  the  pressure  within 
the  apparatus  was  again  reduced  to  one-third,  and  the  distillation 
continued,  this  time  without  any  attempt  to  register  the  tempera- 
tures of  the  distillates  when  the  partial  vacuum  was  destroyed  in 
order  to  change  the  receivers,  and  another  receiver  had  been  at- 
tached to  the  condenser  and  heat  reapplied,  it  was  plain  to  see  that 
the  temporary  cooling  of  the  gum  had  the  effect  of  causing  its  de- 
composition into  lower  boiling  substances. 
Three  other  distillates  were  collected.  These  varied  in  color,  and 
apparently  in  specific  gravity,  as,  when  a  few  drops  of  one  distillate 
fell  into  the  portion  preceding  it,  the  two  liquids  could  be  seen  upon 
stirring.  The  first  of  these  liquids  had  a  pale  yellow  color;  the  sec- 
ond a  yellow  color,  the  third  was  more  yellow  than  the  second,  and 
the  fourth  was  of  a  greenish  color. 
Besides  the  water,  which  distilled  over  when  the  gum  was  heated, 
each  of  the  four  fractions  which  were  obtained  was  mixed  with 
water,  and  it  was  noticed  that  the  amount  of  this  seemed  to  bear  a 
definite  relation  to  the  volume  of  the  fraction.  All  the  distillates 
had  odors  suggestive  of  acrolein. 
In  order  to  obtain  these  distillates  it  was  necessary  to  push  the 
temperature  to  a  point  where  the  residue  in  the  flask  was  a  thick, 
tarry  substance,  possessing  a  petroleum  residuum  odor.  Upon  allow- 
ing this  residue  to  cool  it  became  solid.  This  residue  constituted 
1-89  per  cent,  of  the  weight  of  gum  taken. 
The  first  fraction  obtained  in  the  above  distillation  was  redistilled 
under  a  pressure  of  250  millimetres.  The  distillate  obtained  from  it 
passed  over  between  ioo°  C.  and  3100  C,  the  temperature  rising 
gradually  during  the  process. 
The  second,  third  and  fourth  fractions  were  also  refractioned,  but 
it  was  impossible  to  register  the  boiling  points  of  the  distillates  ob- 
tained from  them,  although  they  were  distilled  under  as  little  as  200 
millimetres  to  250  millimetres  pressure. 
