62 
THE  TROPICAL  AGRICULTURIST 
[July  i,  1892- 
A sample  of  rubber  from  H.  brasiliensis,  grown  at 
Mergui,  India,  was  reported  upon  in  this  country  in 
1889  as  worth  Is.  l\cl.  per  lb. 
Ceara  rubber  or  “ Ceara  Scrap"  is  afforded  by 
Manihot  Gladovi,  Muell.  Arg.,  a tree  native  of  South 
America  and  belonging  to  the  natural  order  Eu- 
phorbiacece.  The  imports  of  this  rubber  into  this 
country  amounted  to  180  tons  in  1891.  In  Case  96, 
Museum  No.  1,  will  be  found  samples  from  Brazil, 
and  also  from  plants  introduced  into  Ceylon,  Zanzi- 
bar, and  Natal. 
Mangabeira  or  Pernambuco  rubber  is  extracted 
from  a small  tree  (Hancornia  speciosa , Gomez.)  of 
the  natural  order  apocynaceee.  Specimens  of  this  rub- 
ber are  shown  in  Case  72,  Museum  No.  1. 
The  principal  source  of  Central  American  rubber 
is  Castilloa  elastica,  a large  forest  tree  of  the  tribe 
Artocarpece  of  the  natural  order  Urticacece.  It  affords 
the  Ule  of  British  Honduras  as  well  as  Nicaragua, 
Guatemala,  Mexico,  and  Guayaquil  rubbers.  The 
total  imports  of  Central  American,  West  India, 
Columbian,  Carthagena,  and  Guayaquil  rubbers  dur- 
ing the  year  1891  amounted  to  100  tons.  See  Case 
100,  Museum  No.  1. 
Esmeralda  of  Guiana  may  perhaps  be  afforded  by 
Hevea  sp.  or  Sapium  sp.  of  the  natural  order  Eupliorbi- 
axut. 
Colombian  india-rubber  and  “Carthagena"  are  one 
and  the  same  thing,  as  is  pointed  out  in  the  Kew 
Bulletin,  1890,  p.  149.  The  tree  yielding  this  rubber, 
is  Sapium  biglandulosum  of  the  natural  order  Euphorbi- 
acece,  a widely  spread  and  variable  species ; it  is 
also  the  source  of  Touckpong  or  Cumakaballi  rubber 
of  British  Guiana.  Case  96,  Museum  No.  1.  con- 
tains specimens  of  these  rubbers. 
Assam  rubber  is  the  produce  of  Ficus  elastica.  a 
large  tree  of  the  Artocarpece  tribe  of  Urticacece.  The 
imports  of  Assam  and  Rangoon  rubber  (also  from 
F.  elastica)  amounted  to  350  tons  in  1891.  Speci- 
mens may  be  seen  in  Case  99,  Museum  No.  1. 
Borneo  rubber  is  afforded  by  species  of  Willughbeia 
and  Leuconohs,  allied  general  of  the  order  Apocynace 
(see  Kew  Report  1880,  p.  43)  ; 200  tons  of  this  rub- 
ber were  imported  into  this  country  during  the  year 
1891.  Samples  will  be  found  in  Case  71,  Museum 
No.  1. 
African  rubber  is  furnished  by  several  species  of 
the  genus  Landolphia , woody  climbers  of  the  natural 
order  Apocynaceee.  The  best  quality  from  the  Zanzibar 
coast  is  derived  from  L.  Kirhii ; two  other  species, 
viz.,  L.  flonda  (the  chief  source  of  Mozambique 
rubber),  and  L.  petersiana  are  also  sources  of  the 
East  African  supply. 
On  the  West  coast  L.  oicariensis,  which  has  a very 
wide  distribution,  is  the  principal  species  furnishing 
Congo  and  Sierra  Leone  rubbers.  L.  flonda,  which 
occurs  on  the  east  coast,  and  L.  Mannii  also  afford 
part  of  the  West  African  supply.  Liberian  rubber 
is  perhaps  in  part  afforded  by  the  “Abba”  tree 
(Ficus  Yogelii),  of  the  Artocarpece  tribe  of  Urti- 
cacece, and  has  already  been  fully  discussed  in  the 
Kew  Bulletin  for  November  1888  and  May  1890. 
Messrs.  Hecht,  Levis,  and  Kahn  give  the  follow- 
ing satistics  concerning  these  rubbers  for  1891,  viz. : — 
African  imports,  4,350  tons  ; Mozambique,  380  tons ; 
Madagascar,  300  tons.  Case  71,  Museum  No.  1, 
contains  samples  of  these  rubbers. 
The  following  review  of  the  sources  of  rubber 
supply  from  the  commercial  side  has  appeared  in 
The  Indiarvbber  and  Gutta  Bereha  and  Electrical 
Trades  Journal,  January  8,  1892 : — ■ 
There  are  merchantable  in  New  York  between 
30  and  40  different  sorts  of  indiarubber,  the  vari- 
ations determining  the  selection  by  manufacturers 
in  the  purchase  of  stocks,  says  I.  A.  Sherman  in 
the  Indiarubber  World.  Of  course,  rubber  in  all 
its  variations  is  essentially  the  same,  differing  some- 
what in  the  same  degree  as  the  pumpkin  in  South 
Dakota  from  that  in  New  Englaud — one  large  and 
another  small,  one  with  little  flavour  and  the  other- 
richer  in  food  qualities.  The  difference  between  sorts 
of  rubber,  however,  is  due  in  large  measure  to  the 
methods  employed  in  gathering  the  sap.  It  happens 
that  the  natives  of  the  Amazon  Valley  have  always 
taken  pains  in  the  curing  of  rubber.  While  climatic 
conditions  in  that  country  may  have  had  their  in- 
fluence upon  the  character  of  ' Para,”  the  condition 
in  which  this  rubber  is  exported  has  become  a prime 
factor  in  making  it  a favourite  with  manufacturers. 
On  the  other  hand,  some  of  the  African  sorts  are 
so  full  of  bark  and  stones  as  to  make  them  almost 
, unfit  for  use.  At  one  time  “Assams”  were  almost 
, unmarketable  in  New  York,  the  price  sinking  as  low 
as  10  cents  per  pound,  and  not  wanted  at  that.  One 
firm,  after  long  experimenting,  discovered  a cherni- 
cial  solution  in  which  the  rubber  was  washed,  the 
process  being  that  the  bark  and  other  impurities 
absorbed  the  chemicals,  making  them  so  heavy  that 
they  separated  from  the  gum  and  fell  to  the  bottom 
and  away.  This  company  made  a fortune  in  a moderate 
space  of  time  : but  they  put  up  gradually  the  price 
of  Assams,  from  the  fact  of  their  creating  a demand 
for  that  sort  of  rubber,  until  the  profits  became 
comparatively  small,  when  they  disposed  of  the  pri- 
vilege of  washing  to  some  leading  rubbermen,  who 
use  the  process  at  the  present  day. 
Para  rubber  is  more  largely  consumed  in  the  United 
States  than  any  other.  It  may  be  noted,  also,  that 
the  larger  share  of  tie  rubber  exported  from  Para 
comes  to  this  couutry.  There  are  three  grades — fine, 
medium,  and  coarse.  Fine  Para  is  the  standard  by 
which  all  other  grades  are  measured ; it  brings  the 
best  price,  and  probably  is  more  used  than  any  other. 
Should  it  become  irregular  in  quality  in  the  oper- 
ation of  curing  over  the  smoke  of  palm  nuts — as 
when  little  strips  of  virgin  gum  occur  in  the  grain 
— it  is  called  “medium,”  ana  its  price  is  lessened 
by  a cent  or  two  per  pound. 
The  “ coarse”  is  imperfect,  being  composed  of  the 
scrapings  and  refuse  of  the  fine  sorts,  and  sell  for 
about  two  thirds  of  the  price  of  the  better  grade.  It 
shrinks  considerably,  having  much  water  in  it,  and 
the  importer  generally  is  in  a hurry  to  turn  it  over 
to  the  manufacturer.  There  are  again  many  vari- 
ations in  Para  rubber  coming  from  different  localities 
on  the  Amazon.  This  sabject  is  involved  in  some 
obscurity  ; but  the  best  rubber  is  supposed  to  be  found 
on  the  River  Purus,  a tributary  of  the  Amazon, 
having  its  source  in  the  Andes."  Brazilians,  how- 
ever, are  apt  to  believe  that  the  locality  of  the  best 
sorts  is  unknown  to  Americans,  and  possibly  the 
Purus  may  not  be  the  locality. 
There  comes  from  Peru,  at  the  sources  of  the 
Amazon  and  its  tributaries,  a rubber  resembling 
the  Nicaragua  sheet,  and  called  Caucho.  This  rub- 
ber is  very  wet,  and  consequently  shrinks  vex-y  much, 
which  is  a serious  drawback.  It  is  considered  a good 
strong  rubber,  and  it  is  utilised  to  a considerable 
extent  by  the  boot  and  shoe  manufacturers. 
Of  Ceara  rubber,  there  are  three  grades,  numbered 
one,  two,  and  three  l-espectively.  It  is  called  a “mule 
gum,”  the  significance  being  that  it  is  neither  one 
thing  nor  the  other,  it  being  so  deficient  in  elasticity 
as  to  cause  some  to  argue  that  it  is  not  rubber.  It 
is  a very  dry  rubber,  its  gathering  being  peculiar. 
The  tree  is  incised  at  the  beginning  of  the 
dry  season,  and  as  the  gum  oozes  from  the  want  it 
forms  on  the  outside  of  the  bark,  to  be  pulled  off  at 
the  end  of  the  season.  The  gathering  of  this  rubber 
seems  to  be  on  the  wane,  for  every  year  there  is  an 
extensive  migration  of  Ceara  people  to  Para,  bound 
for  the  forests  of  the  Amazon. 
From  Bahia  and  Pernambuco,  in  Brazil,  comes  a 
rubber  of  a different  grade  from  that  of  Para.  It 
is  cured  with  alum  and  salt  water.  The  Pernambuco 
comes  in  sheets,  and  is  of  a yellow-white  tinge.  That 
from  Bahia  is  not  so  good,  and  comes  in  round 
balls.  The  principal  objection  to  it  is  that  it  is 
very  damp,  entailing  a large  loss  to  the  importer 
from  shrinkage 
Of  Mangabeira  rubber,  there  are  three  grades,  very 
similar  to  the  Bahia  and  Pernambuco  sorts.  A grade 
that  has  a red  look  is  considered  superior,  and  sells 
for  5 or  10  cents  per  pound  higher  than  the  others. 
From  Central  America  comes  a variety  of  rubbers, 
distinctive  in  name  theoretically,  but  owing  to  the 
lines  of  transportation  centering  at  Greytown,  and 
the  transshipment  at  that  point  to  New  York, 
there  is  much  confusion,  one  sort  often  getting  sub- 
