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aware  that  this  has  been  attributed  to  the  comparatively  large  size 
of  the  rubber  globules  in  the  Castilloa  latex,  but  for  reasons,  based 
upon  evidence,  I shall  produce  in  another  paper  on  this  important 
subject,  I believe  this  assumption  to  be  erroneous. 
In  my  communication  I showed  that  the  latex  of  an  11  year  old 
Castilloa  tree  contains  31  per  cent,  of  pure  rubber,  and  it  will, 
therefore,  be  seen  from  the  above  statement  regarding  the  amount 
of  albuminous  matter  in  the  latex  that  if  we  coagulate  the  latter 
•without  first  removing  from  it  this  albuminous  matter  we  obtain  a 
rubber  containing  over  25  per  cent,  of  albuminous  matter.  The 
native  rubber  collectors  prepare  the  rubber  from  the  latex  in  such 
a way  that  at  least  part  of  the  aqueous  vehicle  of  the  latex  is  drained 
away  before  coagulation  takes  place,  and  consequently  we  never  find 
a Central  American  rubber  (crude)  which  contains  as  much  as  the 
above  stated  quantity  (25  per  cent,  of  albuminous  matter),  but  lots 
containing  from  9 to  13  per  cent,  are  quite  common.  It  is  indeed 
the  presence  of  such  a large  amount  of  albuminous  matter  in  the 
Central  /\merican  and  some  other  Castilloa  rubbers  which  is  largely 
responsible  for  their  frequently  reaching  American  and  European 
ports  in  a state  of  pronounced  putrid  fermentation,  of  the  atrocious 
smell  they  emit  on  washing,  and  of  their  often  very  unsatisfactory 
behaviour  in  the  process  of  vulcanisation.  When  such  rubber  in 
a state  of  advanced  putrid  fermentation  is  subjected  to  the  wash- 
ing process  a very  considerable  proportion  of  the  coagulated  albu- 
minour  matter,  rendered  soluble  by  the  fermentation,  is  removed, 
but  the  rubber,  although  not  taking  itself  an  active  part  in  this  fer- 
mentation, is,  nevertheless,  found  to  have  suffered  more  or  less 
severely  from  it,  to  possess  little  strength,  and,  after  vulcanisation, 
only  very  moderate  distensibility  (elasticity).  If,  on  the  other  hand, 
the  rubber  reaches  the  factory  in  fair  condition,  it  contains  prac- 
tically the  whole  of  the  albuminous  matter  in  an  insoluble  condition 
and  so  intim.ately  intermixed  with  the  rubber  that  the  washing  al- 
together fails  to  remove  more  than  a mere  trace  of  it.  We  obtain 
then  a washed  rubber,  which  contains  a very  large  proportion  of 
albuminous  matter,  the  presence  of  which  in  the  washed  and  dried 
rubber  is  scarcely  noticeable,  but  which  is  the  cause  of  such  rubber 
forming  invariably  a peculiarly  “ short  ” and  none-resilient  vul- 
canisation product.  It  will  thus  be  seen  that  whatever  happens  to 
such  rubber  during  transit  it  is  always  a very  inferior  product  from 
what  it  might  be  if  the  albuminous  matter  were  kept  out  of  it.  In 
fact,  I scarcely  think  I want  any  further  justification  for  the  state- 
ment that  the  Castilloa  rubber  of  the  [)resent  day  owing  to  the 
above  discussed  defect,  occupies  a much  lower  position  than  it 
would  hold  considering  the  intrinsic  quality  of  the  pure  rubber  it 
contains.  lam,  indeed,  of  the  opinion  that  properly  prepared. 
Castilloa  rubber  is  superior  to  most  of  the  present  day  Para  grades. 
Incident  dly  I may  remark  here  that  the  pre.sence  of  substantial 
quantities  of  albuminous  matter  not  only  Castilloa  rubber,  but  also 
in  some  other  (.African)  brands,  and  the  odour  they  produce  owing 
to  fermentation  has  given  rise  to  the  now  almost  ineradicable 
nursery  tale  that  in  certain  districts  tlu'  rubber  is  ('oagulaled  by 
