514 
Some  Data  on  Gum  Chicle. 
f  Am.  Jour.  Pharm. 
\  November,  1903. 
subject ;  all  that  was  found  being  some  facts  regarding  its  habitat, 
growth  and  collection,  and  indefinite  statements  of  its  solubility. 
With  this  in  view,  tests  were  made  on  the  sample  at  hand,  which 
purported  to  be  a  purified  gum,  and  the  results  of  them  are  here 
recorded,  in  the  hope  that  additional  data  may  be  elicited  from 
other  sources.  It  must  be  remembered  that  these  tests  were  made 
on  gum  devoid  of  adherent,  and  included  sand,  fragments  of  wood 
and  such  impurities,  hence  these  are  not  comparable  with  those 
from  very  impure  gums.  Further,  the  anomaly  by  which  the  term 
"  gum  "  is  applied  to  a  purely  resinous  exudation  must  be  kept  in 
mind. 
The  tests  made  were  for  ash,  moisture,  solubility  in  various  sol- 
vents, acid  value  and  saponification  value. 
Ash,  obtained  by  direct  ignition  of  i-o  gram  of  gum,  amounted 
to  02  per  cent. 
Moisture  was  determined  by  carefully  weighing  about  i-o  gram 
into  a  tared  wide  mouth  flask  of  100  c.c.  capacity  and  digesting 
with  25  c.c.  ether  at  the  room  temperature  till  all  that  would  had 
gone  into  solution  and  the  insoluble  residue  was  disintegrated.  The 
whole  was  now  put  under  a  hot-air  blast  till  evaporated  to  dryness, 
and  then  heated  at  ioo°  for  four  hours.  The  total  moisture  by  this 
means  was  2-2  per  cent. 
Solubility  was  found  by  leaving  i-o  gram  in  contact  with  150  c.c. 
of  the  solvent  for  twenty-four  hours  with  frequent  agitation,  then 
filtering  through  a  filter  dried  at  100°  and  tared,  washing  the 
insoluble  residue  well  with  the  solvent,  drying  the  filter  and  residue 
at  ioo°  and  weighing.  By  this  means  its  solubility  in  chloroform 
was  found  to  be  827  per  cent.,  and  in  benzol  847  per  cent.  In 
alcohol  it  was  but  slightly  soluble,  and  that  but  slowly. 
The  acid  value  was  determined  according  to  the  indirect  method 
advocated  by  Dieterich,  which,  as  applied  in  this  case,  consisted  in 
dissolving  the  resin  in  chloroform,  adding  to  this  solution  20  c.c.  of 
N / 1  alcoholic  KOH,  letting  stand  for  some  hours  at  room  tem- 
perature with  occasional  agitation  and  then  titrating  the  excess  of 
KOH  by  N / 1  H2S04.  The  acid  value  is  expressed  in  milligrams 
of  KOH,  required  to  neutralize  i-o  gram  of  the  substance,  and  was 
in  this  instance  52. 
The  saponification  value  determined  after  the  manner  used  by 
the  above-mentioned  authority  was  applied  as  follows  :  10  gram  of 
