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ON  THE  EXTRACTION  OF  CAOUTCHOUC. 
ON  THE  EXTRACTION  OF  CAOUTCHOUC. 
By  M.  Weddell. 
Caoutchouc  may  be  obtained  from  a  great  many  plants,  but 
those  which  yield  it  in  any  abundance,  are  comparatively  few  in 
number.  They  belong  to  the  natural  orders  Artocarpse,  Apo- 
cynacese,  and  Euphorbiaceee,  and  inhabit  all  the  warmest  parts 
of  the  earth. 
In  Artocarpese  we  have, 
Castillea  elastica  (Cerv.)  of  Mexico, 
Cecropia  peltata  (Linn.)  of  Tropical  America, 
And  various  fig-trees  of  Asia  and  America,  of  which,  however, 
Ficus  elastica  is  the  only  important  one,  being  the  principal 
source  of  caoutchouc  in  the  East  Indies. 
In  Apocynacece  there  is, 
Urceola  elastica  (Roxb.)  which  •  furnishes  the  Borneo  and 
Sumatra  India-rubber,  known  in  commerce  as  Singapore  or  Pulo- 
Penang  India-rubber. 
Vahea  gummifera  (Poir.),  the  source  of  Madagascar  India- 
rubber ;  and  Hancomia  spinosa  (Gomez.),  from  which  I  saw  a 
large  quantity  collected  in  the  interior  of  the  Brazils. 
Belonging  to  Euphorbiacece  we  have  the  well-known  Siphonia 
elastica,  or  Hevea  guyanensis,  which  yields  the  largest  amount  of 
commercial  caoutchouc,  known  in  commerce  as  Para  Indian-rub- 
ber, from  its  being  imported  from  Para,  a  small  port  situated  at 
the  mouth  of  the  Amazon  river. 
This  tree,  which  grows  extensively  on  the  plains  of  the  Oronoco 
and  Amazon  rivers,  will  be  one  to  which  my  remarks  will  be  ex- 
clusively confined.    Siphonia  elastica,  or  the  Syringe-tree*  of 
*  The  origin  of  this  name  is  given  in  L'Uistoire  de  VAcademie  Roy  ah 
des  Sciences,  1751,  page  18,  in  the  following  terms  : — 
"  The  Omaquas,  a  tribe  inhabiting  the  borders  of  the  Amazon  river, 
make  an  extraordinary  use  of  this  exudation.  They  form  it  into  pear-shaped 
bottles  or  bulbs,  in  the  neck  of  which  they  fasten  a  hollow  wooden  tube  >, 
upon  filling  the  bulb  with  water,  and  then  pressing  it  with  the  hand,  the 
water  is  forced  out  at  the  mouth  of  the  tube,  forming,  in  this  way,  a  com- 
plete syringe.  It  is  considered  by  these  people  an  ordinary  mark  of  polite- 
ness for  a  host  to  present  to  each  of  his  guests  one  of  these  bottles  filled 
with  warm  water,  and  which  they  do  not  fail  to  make  use  of  before  dinner. 
This  strange  custom  has  led  the  Portuguese  to  name  the  tree  which  pro- 
duces this  resin,  Pas  de  xiringa,  or  syringe  wood." 
