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the  vvashwater  in  the  form  of  a snow-white  cake  of  rubber  of  such 
strength  and  toughness  that  it  can  in  one  mass  be  lifted  out  from 
the  barrel.  On  cutting  this  cake  open,  it  will  be  found  that  it  is 
rather  spongy,  being  full  of  little  holes  which  are  still  filled  with 
some  of  the  albuminous,  though  very  dilute,  mother  liquor.  If, 
therefore,  the  rubber  were  dried  in  this  state  it  is  obvious  that  it 
would  still  contain  a small  quantity  of  the  objectionable  albuminous 
matter.  For  this  reason  the  rubber  contained  should  at  once  be 
taken,  cut  into  strips,  and  subjected  to  a thorough  washing  upon 
an  ordinary  rubber  washing  machine.  As  all  albuminous  matter 
present  is  still  in- a state  of  perfect  solubility  there  is  no  difficulty 
whatever  of  completely  removing  every  trace  of  it  by  carrying  out 
the  washing  with  a plentiful  supply  of  water  on  the  washing  rollers. 
The  rubber  thus  obtained  is  a product  of  a degree  of  purity  in 
which  no  rubber,  not  even  the  finest 'brands  of  Para,  has  ever  been 
offered  to  the  manufacturer.  It  is  absolutely  free  from  solid  im- 
purities of  any  description,  it  contains  no  trace  of  either  soluble  or 
insoluble  organic  or  inorganic  impurities.  Of  course  it  contains  a 
small  amount  of  resinous  matter  combined  with  only  a trace  of  the 
constituents  known  as  ^^ash.^^  The  amount  of  these  resinous  mat- 
ters is  extremely  small,  and  they  are  of  an  entirely  innocuous 
nature,  so  that  any  attempts  to  remove  them,  which  would  call  for 
a somewhat  energetx  chemical  treatment,  would  be  altogether  out 
of  place.  In  a further  communication  I intend  to  give  the  analy- 
tical data  of  this  pure  Castilloa  rubber. 
When  dry,  the  condition  in  which  the  owners  of  the  Las  Cascadas 
plantations  intend  to  ship  this  rubber,  it  forms  a product  which  re- 
quires no  preparatory  operation  on  the  part  of  the  rubber  manu- 
facturer, but  which  may  at  once  be  taken  into  operation  for  the 
manufacture  of  rubber  goods  of  every  description.  Nor  need  any 
fear  be  entertained  that  rubber  of  this  description  is  in  the  least 
liable  to  suffer  such  detrimental  changes  during  transit  in  the  ships’ 
holds,  which  are  at  present  so  common  owing  to  the  ‘"heating” 
(fermentation)  of  the  rubber  during  transit.  Indeed,  a considerable 
lot  of  this  which  was  purposely  packed  and  shipped  in  the  exces- 
sively wet  condition  in  which  it  came  off  the  rubber  washer,  had  not 
undergone  the  least  change,  still  less  any  deterioration  on  reaching 
this  country. 
An  analysis  of  a sample  taken  of  one  of  these  dry  sheets  for  rub- 
ber gave  the  following  results  : — 
Resinous  Matter  - . - 
Ash  - - - - - 
Nitrogfenous  Constituents 
o 
2'6i  p.c. 
0*44  p.c. 
Nil. 
Nil. 
Insoluble  Constituents 
The  sheets  themselves  are  extremely  light  in  colour,  semi-trans- 
parent, and  when  dissolved  in  the  usual  rubber  solvents  form  almost 
(jlass  clear  solutions.  'Ihe  characteristic  rubber  smell  is  almost 
entirely  lacking,  certainly  much  less  noticeable  than  in  even  the 
finest  Para  rubber.  The  strength  of  these  sheets  is  distinctly 
superior  to  that  of  washed  and  dried  sheets  of  Para  rubber.  How 
this  Castilloa  rubber  after  vulcanisation  compares  with  Para  rubber, 
