The times., 1901-04-28

eIastica. in common use, for decorative
purposes, thrives in Porto Rico. and
grows TO a large size: though the wood is
soft and the trees suffer in the hurricane.
Plantations of this tree. while requiring
from fifteen to twenty years to reach full
bearing. have proved profitable in the
Malay Peninsula. In West Africa a very
similar and equally beautiful native spe-
cies is known to yield rubber. There are
several other species of rubber plants
growing wild in Porto Rico which have
been utilized by the Porto Ricans as shade
trees. The amount of rubber Obtainable
from these trees has been small. but il is
believed more could be obtained by tapping
in the rainy season. The figs Of these rub
readily from cuttings. and there are other
rubber yielding trees which may be prOpa-
gated in this way
IN AN EXPERIMENTAL STAGE.
There are many alluring possibilities
which have been or might be suggested,
but all are still in the experimental stage,
to say nothing of the fact that Porto
Rican conditions are entirely untried.
In order to meet in advance this last diff
ffcuity and to make possible the early
provision of seeds and propagating stock
wherever the utility of a species can be
demonstrated, it is eminenuy desirable
that a collection of rubber producing
plants be maintained in Porto Rico, and
that it be begun at the earliest possible
date. The seeds of many tropical trees
are extremely short lived and viii not
Withstand drying By packing in spe-
cially prepared cases in which they can
germinate en- route, it may be possible
to send them long distances; but such
shipments. well as those of young
plants, are expensive and unsafe, and
the vitality of the young Seeding is often
injured when not entirely destroyed,
thus partially vitiating experiments and
rendering il impossible or extremely
costly to import large quantities of de-
sirable seeds in case a general demand
should arise for a particular species.
Considered from the viewpoint of the
utility of rubber for those who may
undertake intelligent mixed farming in
the tropics, it will be worth while for
owners of plantations to begin expert
mental paintings of the most promising
rubber trees now known and of others as
fast as they are announced by explorers
and exDerimenters. Without such local
experiments the desirability of more
general planting cannot be known with
sufficient certainty TO JUSTIFY large eX-
penditure or the use of valuable land
should the industry reach the point where
this would be advisable anywhere in
Porto Rico.
The question of rubber cultivation is
not complicated alone by the number OF
different species involved and their
varied requirements for the production
of the largest quantity of milk me
work of drawing the milk and extracting
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main, a large element of labor and eX-
pense which cannot be overlooked with
safety in planning for the inauguration
of a new industry. In the coIectloh OF
the new supply, the practice of cutting
down the trees has been general, but
even the savages have in some instances
seen the advantage OF not destroying so
valuable an asset, and various processes
of tapping have been tried. In many
cases these are but q slight Improvement
over the former method. since the injuries
are so severe as to seriously weaken the
tree while its wood Is exposed in deep
gashes to the attacks of destructive
fungi and insects.
To secure maximum profits, cultural at
tempts with rubber must be combined
with improvements In methods OF mar
vesting, the yield of the rubber orchard
for any one season being entirely secon-
dairy to the question Of its perpetuatlon
and continued producuFeness. Some trees
weld their milk freely. while others eXude
but little and must be repeatedly tapped,
necessitating much greater labor in col
lecting IN some the bark closes readily,
while in others injury is more permanent
and new places must be tapped each sea-
son. The advantages of longitudinal,
obliQue. and transverse cuts have also
been considered, but mostly from the
view point OF wild trees. where. the maxi
mum yield without actual destruction is
usually the limit Of caution. Various i'm
proved axes and knives have been de-
yised, but most of these have been ad-
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has come into general use.
Under cultural conditions the expense Of
the milk will be increased, since
the continued health of the trees Will
necessitate the extraction of smaller
q mounts OF milk, with the use of better
tools and the exercise Of more care In the
process. all Of which means more. as well
as higher priced, labor There may, of
course. lie cOmpensating advantages If
tools of sufficient excellence can be in
vented and also in the fact that the trees
will be closer together than IS usual IN
the wild state. But labor employed in
civilized community is in any event likely
TO be much more expensive than that
now utilized in the work Of rubber gath
ering, most of which is performed in
their own unValued time by the natives
OF uncivilized regions, who barter the
product for manufactured articles, which
are 10 them merely iuXurles.
No less important are the needs OF In
vestigaJiOn and the attendant possible
ties Of progress in the matter of extract
ing rubber from the milk. II is in this
department that the increased expense OF
drawing and collecting the juice may pc
compensated IN regular culture by the
better opportunities for applying i'm
proved methods of extraction which viii
secure all the rubber and render a prod
uct of the best quality. IL necessary ali
the milk of an orchard or of whole ag-
ricultural section might be treated in one
establishment, d rubber dairy, so TO
speak.
quite similar 10 animal milk in that il
consists Of a liquid in which float minute
glObules Of q different composition which
tend TO separate as soon as the physical
or chemical conditions Of the suspendng
fluid are changed. The term coagulatiOn
is accordingly applied, although the Un-
derlying changes may be entirely differ
ent not only In milk and rubber but also
in the different kinds of rubber. The sap
Of some trees separates Immediately on
exposure TO the atmosphere, and drop
taken between the thumb and finger Will
show at once line elastic strands. The
natives of Angola are thus able to gather
considerable quantities Of rubber simply
by smeaFing the juice over their bodies.
After coagulation has taken place the
gum is peeled off in sheets, which are
considered good quality by the trade.
Ceara rubber, also, receives no special
treatment The milk is allowed 70 dry
on the tree or run down its side and col
lect in little hOllOws in the ground pro-
tected from the soil only by a few leaves.
The Para rubber does not so readily CO.
agulate II is caught in small clay cups,
which are plastered to the trees with mud.
The sap Is then collected in buckets and
exposed 70 strong smoke on a paddle
shaped piece Of wood, which is alternately
dipped in the milk and held over the fire
The same process has been applied in
Brazil TO the sO-Called Pernambuco rub
Der and succeeds also with Ceara, but il
is nov considered too slow and laborious.
Some claim that the heat after all is the
only effective part Of IT.. and that the
SCOT constitutes an undesirable impurity
Others insist that the acetic acid OF the
smoke causes the cOagulation and that
the creOsote preserves the rubber from
decay a weak solution of alum as a
solidifying agent has been advocated the
surplus moisture incorporated between
the adhcring particles being removed by
hydraulic or other strong pressure.
THE YIELD OF CENTRAL AMERICA.
The Castloa rubber Of Central Ameri-
weeks or more being required for natural
changes 10 hiring a about the soma ration of