A NEW  RUBBER  INDUSTRY. 
The  extraordinary  demand  for  rubber,  induced  alike  by  the 
many  new  uses  to  which  this  product  is  put  and  by  the  gradual 
shrinkage  of  the  world’s  supply  of  uncultivated  rubber  produc- 
ing trees  has  caused  a close  scrutiny  to  be  made  of  other  avail- 
able sources  of  supply.  The  manufacture  of  artificial  rubber  is 
about  as  far  off  as  the  production  of  synthetic  camphor  or  sugar 
and  therefore  little  help  is  to  be  looked  for  in  this  direction.  How- 
ever, there  have  been  found  to  be  other  rubber  trees  than  the 
recognized  commercial  and  cultivated  varieties  and  of  these  two 
or  three  promise  to  be  of  great  value. 
As  is  well  known  the  rubber  of  commerce  is  the  dried-  milky 
juice  or  latex  of  various  trees  and  plants.  This  fluid  is  present  to 
a greater  or  less  extent  in  many  varieties  of  trees,  plants  and 
creepers.  It  is,  however,  only  a few  varieties  which  yield  it  in 
sufficient  quantity  and  of  a certain  quality  which  are  of  any  great 
account  as  producers  of  commercial  rubber. 
Of  an  entirely  different  kind  is  the  rubber  produced  from  a 
Mexican  plant  known  as  the  guayule  bush  (Parthenium  argeu- 
tatum).  This  plant  occurs  wild  in  great  profusion  and  attains 
the  height  of  about  three  or  four  feet  in  the  desert  plains  of 
Mexico  and  Southern  Texas.  The  Indians  had  long  obtained  a 
gum  or  rubber  from'  this  plant  by  means  of  chewing  the  bark  and 
this  custom  no  doubt  suggested  the  commercial  value  of  the  tree. 
As  has  been  inferred  the  guayule  posesses  no  latex.  The  rub- 
ber is  distributed  in  minute  granules  throughout  the  system  of  the 
plant,  the  bark  containing  the  largest  deposits.  In  order  to  ob- 
tain these  granules  and  separate  them  from  the  woody  tissue, 
various  processes  are  resorted  to,  the  operations  of  which  are  sur- 
rounded with  great  secrecy.  Speaking  generally  extraction  is 
conducted  by  grinding  and  subsequent  maceration  in  a solvent  of 
the  rubber. 
To  obtain  the  product  the  whole  of  the  plant  is  destroyed.  Dur- 
ing the  last  five  years  a very  large  quantitv  of  guayule  rubber  has 
been  produced.  Several  large  firms  are  now  in  operation  and  as 
a consequence  the  available  land  covered  with  wild  shrubs  is 
being  rapidly  encroached  upon.  However,  there  is  yet  sufficient 
to  meet  demands  for  many  years.  In  1905  the  value  of  this 
variety  of  rubber  shipped  from  one  port  alone  amounted  to  up- 
wards of  $125,000.  Three  years  later  there  was  shipped  from  the 
same  port  guayule  rubber  valued  at  eighteen  times  as  much. 
At  present  there  seems  no  great  prospect  of  the  guayule  rubber 
industry  becoming  a permanent  competitor  with  latex  rubber,  as 
every  year  finds  the  wild  supply  diminished  and  experiments  at 
cultivation  have  been  discouraging.  The  germination  of  the  seed 
is  very  unsatisfactory,  by  far  the  greatest  proportion  failing  to 
come  up.  The  process  of  cultivation  also  greatlv  impairs  the 
quantity  of  rubber.  With  the  wild  bushes  several  years  are  re- 
