June  i,  11193.] 
THE  TROPICAL  AGRICULTURIST. 
755 
GAMBIE. 
(From  the  Agricultural  Bulletin, of  the  Malay  Peninsula). 
( Concluded  from  page  G88 ). 
Chemical  Composition. 
Fluckiger  and  Hanbury  ( Pharmacographia , p.  337) 
state  that  gambir  in  composition  agrees  with  cuteh 
( Acacia  catechu),  and  especially  with  the  pale  variety 
made  >n  Northern  India.  Both  consist  mainly  of 
catechin,  and  the  yellowish  colouring  matter  was 
determined  by  Hlasiwetz  and  Lowe  to  be  quercetin, 
also  occurring  in  cutch. 
The  results  of  quantitative  analyses  vary  to  a 
certain  extent  according  to  the  method  used.  In  the 
analysis  of  Messrs.  Evans  and  Dr.  Hamburgh  the 
methods  employed  are  not  given,  so  it  is  difficult 
to  compare  these  aualyses  The  latter  gives  also 
an  analysis  of  Singapore  gambir,  cube  No.  I in  bags, 
which  may  be  compared  with  Mr.  Evans’  analysis 
of  Singapore  gambir  : — 
Water 16.2  per  cent. 
Ash  ...  ..  ..  ..  ..  3'9  „ 
Catechin  . . . . . . . . 42.0  ,, 
Catechu- tannic  acid 5.9  ,, 
Other  organic  matter  . . . . 32.0  about. 
„ ,,  insoluble  in  alcohol  161 
„ „ in  water  5.5 
121.6 
and  expressing  the  little  juice  obtained  on  a glass 
slide.  From  this,  I gather  that  the  catechin  in  the 
living  leaf  is  in  a state  of  solution,  and  is  crystal- 
lized only  on  friction. 
The  leaves,  which  are  very  rich  in  chlorophyll, 
become  brown  very  rapidly  when  bruised.  A trans- 
verse section  shows  that  this  is  not  due  to  the  al- 
teration of  chlorophyll,  but  to  the  alteration,  pro- 
bably oxidation  of  the  other  cell  contents,  probably 
the  liquid  containing  the  catechin,  which  becoming 
brown  masks  the  green  chlorophyll. 
When  the  leaf  is  brown,  no  catechin  remains,  so 
that  I gathered  that  the  catechin  is  only  stable  in 
the  form  of  crystals,  and  that  the  liquid  containing 
the  catechin  is  rapidly  destroyed  by  oxidation. 
In  conclusion,  I may  state  that  the  chemical  in- 
vestigation of  gambir  during  the  various  stages  of 
the  growth  of  the  plant  and  preparation  of  - the 
extract,  has  been  taken  up  by  Dr.  Bott.,  Govern- 
ment Analyst  of  the  Straits  Settlements.  We  may, 
therefore,  look  forward  before  very  long  to  a paper 
dealing  fully  with  the  chemistry  of  gambir,  the 
knowledge  of  which  at  present  must  be  considered 
incomplete  and  in  some  respects  even  indefinite. 
At  present  I am  able  to  append  the  results  of 
analyses  by  Dr.  Bott  of  a number  of  samples  of 
gambir,  and  to  add  a few  general  remarks  as  to 
gambir  considered  chemically. 
Analyses. 
The  water  here, is  much  less  than  in  Mr.  Evans’ 
two  samples.  Dr.  Romburgh  says  the  water  in  com- 
mercial gambir  seems  to  vary  from  9.5  to  16  °/0, 
but  it  is  certainly  too  often  more  than  this.  The 
question  of  the  water  I have,  however,  dealt  with. 
The  ash  varies,  says  Dr.  Romburgh,  from  2.5  to 
5.4  %,  and  he  suggests  it  is  influenced  by  the 
amount  of  water  used  in  contact  with  the  gambir. 
Thus  in  Singapore  gambir  made  by  boiling  the  leaves 
in  water  (as  described  above),  ho  found  3.9  ash. 
while  in  Bangka  gambir  made  by  steaming  he  got 
2.6  ash  only.  In  Mr.  Evans’  analysis  the  ash  is 
given  as  very  much  more  than  this,  viz,  6.34  and 
4.46. 
Fluckiger  (1.  c.)  got  2.6  ash  from  some  cube  gam- 
bir, and  this  he  says  consisted  mainly  of  carbonates 
of  calcium  and  magnesium,  but  there  must  be  some 
error  in  this,  as  these  salts  are  not  stable  under 
heat. 
The  catechin  and . catechu-tannic  acids  are,  of 
course,  the  important  factors  iu  the  gambir.  In  Dr. 
Romburgh’s  samples  Singapore  gambir  contained 
less  catechin  and  more  catechu-tannic  acid  than  that 
of  Bangka.  This  difference,  he  says,  is  most  likely 
mainly  due  to  different  modes  of  preparation.  Ac- 
cording to  the  Bangka  method  one  would  obtain 
less  extractive  matter  and  owing  to  the  much  shorter 
exposure  to  boiling  heat,  the  amount  of  catechu- 
tannic  acid  produced  by  decomposition  of  catechin 
(which  change,  appears  to  be  produced  on  protracted 
boiling)  would  be  less. 
Catechu-tannic  acid  is  an  anhydride  of  catechin 
which  can  be  obtained  by  gently  heating  the  latter. 
It  is  soluble  in  water  and  capable  of  decided 
tanning  properties,  precipitating  alkaloids  and  al- 
bumen. it  must,  therefore,  be  remembered  by  manu- 
facturers that  if  a product  rich  in  catechin  is  re- 
quired, excessive  heating  must  not  be  resorted  to. 
Dr.  Romburgli  mentions  an  instance  published 
(but  where  he  does  not  say)  in  Which  a sample 
consisting  of  round  pressed  cakes  of  2 5 to  3 grams 
each,  gave  catechin  only  (40  °/D)  and  no  catechfi- 
tannic  acid.  This  sample  was  said  to  have  coniie 
from  China.  If  so  it  was  probably  not  gambir  at 
all,  as  gambir  is  not  made  in  China. 
If  a leaf  of  gambir  be  rubbed  in  the  hand,  as 
described  before,  a soapy  looking  substance  is  exuded, 
of  a white  colour.  This  put  under  the  microscope 
can  be  seen  to  be  oomposed  of  innumerable  white 
crystals,  very  minute,  acicular,  much  resembling  those 
of  prepared  gambir,  only  smaller.  These  are  crystals 
of  catechin.  They  are  not  visible  in  the  leaf  itself, 
nor  can  they  be  obtained  by  cutting  the  leaf  across 
No.  1 — Malacca  Finger 
Gambir 
No.  2 —Malacca 
(Gambir  pahu) 
Finger  Gambir 
No.  1 quality. 
No,  2 quality. 
Water 
14.50 
13.35 
Ash 
2.92 
3.50 
Catechin 
43.00 
42.00 
Catechu-tannic  acid 
3.00 
■ 5.20 
Organic  matter  other  than 
tanning  principles 
36.58 
35.95 
100.00 
100.00 
No.  3. — Malacca  Finger 
No.  4. — Malacca 
Gambir. 
Flake  Gambir 
(No.  3 quality. 
(Gambir  papan). 
Water 
19.99 
14.25 
Ash 
3.65 
2.80 
Catechin 
42  20 
..  44.00 
Catechu-tannic 
7.30 
'2.80 
Organic  matter 
26-86 
36-16 
100.00 
100.00 
Pale  Gambir  as  received  in  Singapore. 
No.  5.  No  6. 
Water 
36.65 
44.02 
Ash 
3.50  . . 
3.54 
Catechin 
26.10  .. 
20.50 
Catechu-tannic 
9.20  . . 
11.00 
Organic 
24.55 
20.94 
100.00 
100.00 
From  the  above  it  appears  that  No.  3 is  really  the 
richest,  in  tanning  principles,  though  containing 
more  water  than  the  rest,  except  the  very  Wet  bale 
gambir.  The  low  percentage  of  tanning  principles 
in  bale  gambir  should  be  considered,  together  wiht 
the  large  percentage  of  water.  Referring  the  per- 
centages of  tanning  principles  to  the  samples  free 
from  water  we  get  the  following : — 
Contains  total  tanning  principles. 
Dry  No.  1 ..  52.60 
„ „ 2 ..  54.60 
„ „ 3 . . 61.90 
„ „ 4 . . 54.46 
„ ,.5  . . 55.50 
,,  ,,  6 ..  53.30 
It  will  be  seen  that,  but  for  the  large  amount  of 
water,  Nos.  5 aud  6 are  not  bad  gambir  for  tanning 
purposes,  although  for  dyeing  they  might  not  be 
suitable  on  account  of  their  bad  and  uneven  colour 
