S9 
8.  H.  Lutea,  Mull.  D\4rg.  Leaflets  rigidly  membranous, 
obovate-lanceolate,  with  the  base  sharply  cuneate,  shortly  acumi- 
nate, olivaceous-tawny,  opaque,  below  glaucous,  tawny,  glabrous, 
on  both  sides,  of  o m,  lo-om,  0J2  in  length. 
9.  H.  BrasilieNsis,  Mull.  D' Arg.  Leaflets  rigidly  membra- 
nous, lanceolate-elliptical,  oblong-obovate  in  the  middle,  acute  at 
base,  acuminate,  glaucescent,  and  glabrous  below,  of  o rn,  05-0  ny 
07  X o 08  in  length. 
10.  H.  Guyanensis,  Aublet.  Leaflets  membranous,  oblong- 
obovate,  with  the  base  acute  or  cuneate,  obtuse  or  apiculate,  gla- 
brous, shining  above  and  tawny-glaucous  below,  shorter  than  the 
petioles  and  of  om,  25  xo^^  08  in  length. 
The  first  to  have  classified  the  rubber  three  (Hevea  Guianensis) 
was  the  French  Botanist  AuBLET  in  1781,  and  Richard  in  1785, 
who  described  it  by  the  name  of  Caoutchouc.  wSCHRKBER  in  1879, 
not  adopting  AubleTs  description,  created  for  it  the  genus 
Siphonia.  But  LlNN^US  in  1781,  had  already  placed  it  under  the 
genus  Jatropha,  with  the  specific  name  of  elastica,  while  PERSON 
renamed  it  later  on  Siphonia  adding  to  it  LlNN.^lUS’s  specific  name, 
which  WlLLDENOW  eventually  altered  into  cahuchu.  The  name 
Siphonia  elastica  was  the  one  by  which  this  tree  was  more  com- 
monly known  at  the  time  rubbers  belonged  to  the  Hevea,  by  right 
of  priority  and  because  this  said  genus  vSiphonia  was  no  more  than 
a synonym. 
The  names  caoutchouc  and  seringa  belong  to  all  the  species  of 
Heveas,  the  word  caocho  being  to-day  applied  to  the  Castilloas  and 
Galactodendrons.  The  name  coacho,  is,  as  we  have  seen,  a cor- 
ruption of  caaocho'  or  caaochu^  a native  word  derived  from  caa 
wood,  timber,  and  the  verb  0 did  or  0 chu  to  distil,  or  to  run  or 
weep,  in  other  words,  timber  that  weeps. 
In  some  places,  rubber  is  obtained  from  one  species  only  of  the 
local  flora  growing  together,  in  others,  there  is  promiscuity  and  the 
consequent  mixture  of  milks,  from  which  results  the  various 
qualities  of  the  prepared  article,  an  occurrence  common  also  with 
the  oil  of  copaiba. 
Among  the  species  that  produce  the  superior  qualities  of  rubber, 
are  others  called  harrigudas,  which  notwithstanding  that  they  pro- 
duce milk  in  abundance,  is  however,  poor  in  rubber  and  of  bad 
quality  at  that.  This  name  of  harrigudas  is  derived  from  the  fact 
that  some  of  these  trees  have  bellied  on  bulging  trunks,  as  often 
occur  on  the  mari^ins  of  the  Amazon.  The  true  rubbers,  those  that 
produce  rubber  of  the  best  quality,  are  the  H.  Brasiliensis,  the 
H . Discolor  and  the  H . Guyanensis,  ail  of  which  are  rich  in  the 
production  of  a milky  juice,  known  scientifically  as  latex. 
This  milk  is  exuded  from  the  trunk,  the  branch,  the  bough  and 
the  petioles;  however,  it  is  only  that  which  exudes  from  the  trunk 
that  is  of  any  use,  that  from  the  extremities  being  aqueous  and 
poor  in  rubber.  The  nearer  it  is  to  the  ground,  the  greater  the 
abundance  and  the  better  the  quality  of  milk  the  trunk  produces. 
This  milk*  which  constitutes  the  wealth  of  the  tree,  is  a white 
* 
Dissolved  in  small  quantities  in  Castor  oil,  it  has  anthelmintic  properties. 
