544 
ON  THE  EXTRACTION  OF  CAOUTCHOUC. 
Shoes  are  made  in  the  same  manner,  "with  the  exception  that  a 
wooden  mould,  thinly  coated  with  clay,  is  employed — as  it  ad- 
mits of  being  withdrawn  without  breaking.  Ten  minutes  is 
generally  sufficient  for  a  clever  workman  to  make  a  pair  of  shoes. 
I  must  mention,  however,  that  the  effect  of  the  smoke  is  to  co- 
agulate the  caouchouc.  The  hardening  is  afterwards  effected  by 
exposure  for  some  time  to  the  sun. 
Some  experiments  have  recently  been  made  with  a  view  to 
the  exportation  of  this  substance  in  the  liquid  state,  by  inclosing 
it  in  hermetically  sealed  bottles.  Upon  opening  these  bottles, 
however,  a  solid  mass  of  caoutchouc  floating  in  a  serous  liquid, 
presents  itself.  If  the  milky  sap,  as  at  first  extracted,  be  allowed 
to  stand  for  some  time,  it  separates  into  two  portions  in  the  same 
manner  as  milk ;  a  substance  which  it  closely  resembles  in  ap- 
pearance and  taste.  It  may  also  be  drank  without  any  injurious 
effects  being  produced. 
The  most  favorable  period  for  extracting  caoutchouc  is  the 
summer  season,  from  April  to  November.  During  the  wet 
weather  the  work  in  the  forest  is  very  difficult  and  unhealthy. 
The  product  also  is  very  inferior,  containing  much  less  of  its 
solid  coagulable  constituents.  During  the  collecting  season  the 
trees  have  to  be  wounded  afresh  every  day  ;  it  therefore  becomes 
necessary  to  make  the  first  incisions  as  low  down  as  possible, 
because  also,  the  old  wounds  in  healing  frequently  form  a  sort 
of  swelling  round  the  part  which  would  absorb  a  portion  of  the 
descending  sap. 
The  quality  of  these  trees  varies  greatly,  some  yielding  more 
than  others ;  generally,  however,  the  more  sap  there  has  been 
abstracted,  the  more  the  tree  seems  capable  of  yielding.  In  this 
respect  these  trees  resemble  good  cows. 
The  preceding  facts  will  be  sufficient  to  prove  that  the  method 
adopted  by  the  Africans,  Indians,  and  South  Americans  for  ob- 
taining caoutchouc,  is  at  once  simple  and  efficacious.  Every  fact 
in  the  history  of  this  substance  is  calculated  to  stimulate  the  ac- 
tivity of  an  intelligent  explorer,  and  assures  us  of  the  future 
prosperity  of  one  of  the  most -interesting  branches  of  American 
commerce. — London  Pharm.  Journ.  Sept.  1855. 
