The times. [volume] (Washington [D.C.]) 1897-1901, 1901-04-28

eAdSu.s'l. IN common use Tor 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
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 I'm Porto Rico. which have
been utilized by the Porto Ricans as shade
trees. The amount of rubber obtainable
from these trees has beer small. but il Is
believed more could be obtained by tapping
in the rainy season. The figs of these rub
Der trees have the advantage of growing
readily from cuttings, ard tn 're are other
rubber yielding trees which ma V 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
ficulty and to make possible the early
provision of seeds and propagating stock
wherever the utility of a species can be
demonstrated, it is eminently desirable
that a collection of rubber producing
plants be maintained in Porto Rico. and
lidl IL ne ptt.uI ut the earliest ppSSlpAt
date. The seeds of many tropical trees
are extremely short lived and will not
Withstand drying By packing in spe-
cially prepared cases in which they can
terminate en- route, IL may be possible
to send them long distances but such
shipments, as 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 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 experimenters. Without such local
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 The
work of drawing the milk and extracting
the ruDDeT Is. ana VIII undoubtedly It-
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 collection 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 slight improvement
over the former method, since the injuries
are so severe as to seriously weaken the
tree, while it's 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 har-
vesting, the yield of the rubber orchard
for any one season being entirely secon-
dairy to the question Of its perpetuation
and continued productiTeness. Some trees
yield Their milk freely. while others eXude
but little. and must be repeatedly tapped,
necessitating much greater labor in col
Letting 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-
vised, but most of these have been adj
yersely reported upon practice, and none
has come into general use.
Under cultural conditions the expense of
collecting the milk will be increased, since
the continued health of the trees will
necessitate the extraction of smaller
a amounts 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
md "a In the fact thar thu trees
will be closer together than is usual in
the wild state. But labor employed in
civilized community IL 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 luxurles.
No less important are the needs Of In
vestigation and the attendant POSSIBLE
ties of progress in the matter of extract
ing rubber from the milk. 1t Is in this
department that the increased expense of
drawing and collecting the juice may be
compensated in regular culture by the
better opportunities for applying i'm
proved methods of extraction which will
secure all the rubber and render a prod
uct of the best quality. If necessary all
the milk of an orchard or of whole aG-
ricultural section might be treated in one
establishment, a rubber dairy. so to
speak.
The sap OF rubber-producing trees is
quite similar to animal milk in that IL
consists of a liquid in which float minute
glObuleS OF a different composition which
tend to separate as soon the physical
or chemical conditions of the suspending
fluid are changed. The term coaguation
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
.
taken between the thumb and finger Will
show at once fine elastic strands. The
natives of Angola are thus able to gather
considerable quantities Of rubber simply
by smearing 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 10 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.
which are plastered to the trees with mud.
The sap is then collected in buckets and
exposed to 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 now 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. weak solution of alum as a
solidifying agent has been advocated, the
surplus moisture incorporated between
the adhering particles being removed by
hydraulic or other strong pressure.
THE YIELD OF CENTRAL AMERICA.
The Castilloa rubber of Central Ameri-
ca is still more difficult to handle, two
weeks or more being required for natural
changes to bring about the separation of