DEPAETMEIsTT OF INTEEIOE

BUREAU OF GOVERNMENT LABORATORIES.

,..v^

M

CHEMICAL LABORATORY.

THE GUm PERCHA AND RUBBER OF THE
PHILIPPINE ISLANDS.

By Penoyer L. Sherman, Jr., Ph. P.

MANILA:

BTTREAU OF PUBLIC PRINTING.
1903.

8766

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1903.— No. 7.

DEPARTMENT OF INTERIOR.

BUREAU OF GOVERNMENT LABORATORIES.

CHEMICAL LABORATORY.

THE mn PERCHA AND ROBBER OF THE
PHILIPPINE ISLANDS.

Hy I^KNOYEH L. Sherman, .Jr., I^h. I).

MANILA :

lUKi:Ar OF PUBLIC FRINTINCi.

1903.

87G6

3li

S 5 '' ^

LETTER OF TRANSMITTAL.

Department of the Interior,
Bureau of Government Laboratories,

Manila, P. I., September 20, 190S.
Sir : I have the honor herewith to transmit for publication as
a bulletin a monograph on the gutta percha and rubber of the
Philippine Islands, by Penoyer L. Sherman, jr.. Ph. D., chemist
in the Bureau of Government Laboratories.
I am, very respectfully,

Paul C. Freer,
Superintendent Government Laboratories.
Hon. James F. Smith,

Acting Secretary of the Interior.

3

/a -3; -'/*'"

THE QUHA PERCHA AND RUBBER OF THE PHILIPPINE

ISLANDS.

By P. L. Sherman, Jr., Ph. D.

TNTllOl>\JCTIO:S.

The material for this bulletin was collected under the direction
of the Bureau of Forestry and of the Bureau of Government Labora-
tories. As early as 1900 the attention of the Government was called
to the fact that many of the wild tribes in the southern islands were
engaged in cutting down large numbers of forest trees in order
to secure the gutta percha and rubber which they contained.
These products they bartered to the Chinese^ who in turn exported
tliem to Singapore.

The matter was considered important enough to demand inves-
tigation^ because —

( 1 ) The trees were being cut down in violation of forestry rules.

(2) No forestry dues w^re paid by those either collecting or
exporting these forest products.

(3) Judging from the experience of the English and Dutch
in the Malay Peninsula^ Sumatra, and Borneo it would only be
a question of a short time, if the wild tribes were allowed to
have their own way, when there would not be one tree of this
class left standing in the Philippines.

Unfortunately there was no information at hand on the subject.
In June, 1901, I was sent as a special agent of the Forestry Bureau
to Singapore, the Malay Federated States, and Java to study the
laws and conditions under which these forest products were grown,
collected, and marketed.

Provided with the information thus gathered and which is de-
tailed below, upon my return to Manila four months later I was
again sent to the southern Philippines to repeat my investigations
and as before, to make collections of herbarium material and sam-

5

pies of the various kinds and grades of gutta percha and rubber
found there.

This first southern trip consumed several months, for, while
specimens of marketable gutta percha and rubber could be secured
in the principal towns, all herbarium material and gums from
each tree species had to be taken personally to avoid all sources
of error.

The trips along the coasts and rivers of many of the islands
were made in small native sail and row boats, and the journeys
into the forests of the interior were completed on foot with native
guides and carriers. The native gum collectors themselves, their
method of felling the trees and vines, securing the gutta percha
and rubber, preparing the same for market, the prices they received
both . in money and barter were thus seen at first hand, and of
course opportunity secured for making herbarium collections of
the various species of trees and vines yielding gutta percha and
rubber. In the principal towns the market conditions of su])ply,
demand, prices, etc., were studied.

Upon my return to Manila I was ordered to be transferred to the
Bureau of Government Laboratories, in order that all specimens
collected might be tested chemically and physically so as to deter-
mine their relative values. This analytical work, as well as several
subsequent trips to the southern islands, Paragua, Mindoro, and
Culion in search of new material, has been carried out and is
here reported.

The identification of the various species of gutta percha and
rubber trees and vines was kindly undertaken by Mr. E. D. Merrill,
botanist for the Bureau, who also assisted greatly in collecting
herbarium material in Mindoro and Culion.

My thanks are also due to Messrs. J. H. Thigpen and Paul
Stangl for much assistance in the analytical work. To Capt. George
P. Ahem, Chief of the Forestry Bureau, and Dr. Paul C. Freer,
Superintendent of Government Laboratories, T wish to express
warm a})pveciation of their many courtesies and valiuible suggc^s-
tions in planning and carrying out tlie work.

PART I. GUTTA PERCHA.

I. HISTORICAL.

As is the case with many other coniniereial products coming
from Oriental lands, the date of the discovery of gutta percha is
lost in Oriental history. The famous Tradescant Brothers in 1656
(1) exhibited in their museum of curiosities in London a piece
of gutta percha which they had secured in the Far East. Also
in 1822 Dr. William Montgomery (2), an English surgeon, saw
whips and other articles of gutta percha in use by the natives of
Singapore. It is therefore safe to assume that the real discovery
of this remarkable substance was made at some time previous to
either of these dates.

The western or commercial discovery of gutta percha was delayed
until 1843, w^hen both Dis. Montgomery and D^\lmeide sent speci-
mens of the gum and leaves of the tree to London. While the
specimens of D'Almeide were neglected, those of Montgomery re-
ceived enough attention from tlie scientists of tlie Eoyal Society
of Arts to demonstrate some of the uses to wliich the substance
might be put. The botanists agreed that tlie tree belonged to
the family Sapotacew, but as neither flowers nor fruit were at
hand they could go no further with the identification.

In 1847 the greatest advance was made toward the utilization
of gutta percha. Considerable amounts had from time to time
been shipped to London, and experiments were made to determine
its physical and chemical cliaracteristics. T^uckily a sample fell
into the hands of a young German artillery lieutenant, Werner
von Siemens, who was then experimenting with insulating material
for subterranean and submarine telegraphic cables (3). The ease
with which gutta percha lent itself to this object and the high
efficiency obtained induced him to construct a machine for insu-
lating cables. The methods he adopted, as well as the kind of
machinery, have been with few modifications in use ever since.

The subsequent history of gutta percha runs parallel with that
of submarine and subterranean electric cables, for three-fourths of

7

8

all the gutta percha produced has been used on them. With the
construction of the great trans-Atlantic cables in the sixties and
seventies of the past century^ the demand for gutta percha became
enormous, and the details of its value and ready market traveled
over all this part of the Orient.

When the Malay Peninsula adjacent to Singapore failed to supply
sufficient quantities to meet the demand, the adjacent islands of
the Khio Archipelago and Sumatra were invaded, and rich finds
made. Finally Borneo was included in the producing zone, and
lastly the Philippines.

At what date the Philippines began to export gutta percha to
Singapore, the center of the trade, can not be learned with any
degree of certainty. Probably twenty years ago varying quantities
were ,exported, but apparently the trade died out, owing, it is said,
to the wholesale adulterations practiced by the Chinese exporters
and the prohibitory laws of the Spanish Government. For the last
ten years prior to the American occupation of the Islands but
little had been shipped, though the collecting and exporting began
very soon afterwards nnd increased at once -to large proportions.

II. BOTANICAL.

In the year in which Von Siemens made his great discovery of
the insulating value of gutta percha for submarine cables Sir Joseph
Hooker, Bentham, and others worked out the status of the gutta
percha tree. From the first specimen of leaves which had been
sent to England several years previously, it was seen that the tree
belonged to the natural family of Sapotacece (4). The many
species of this family are scattered over the tropical and semi-
tropical world and are distinguished by the curious property all
possess of secreting a milk or latex in the inner layers of the bark.
When the bark is cut or bruised and the capillary sacks and tubes
which contain the latex are ruptured it flows out with greater or
less abundance according to the species of the tree. This milk
probably serves in the plant economy as a protection; still it is
primarily an excretion, since it is discarded by the tree in its dead
leaves and bark and the bark of the live tree can be tapped and the
latex removed with no apparent injury to the tree.

As has been stated, it was in 1847 that specimens of the flowers
and fruit finally reached London and the complete botanical deter-

Fig. 2.— LEAVES OF PALAQUIUM GUTTA BURCK, GROWN AT THE BOTANICAL GARDEN AT SINGA-
PORE, STRAITS SETTLEMENTS. FURNISHES FIRST GRADE GUTTA PERCHA.

Fig. 3 —leaves AND FRUIT OF PAYENA LEERII BENTH. ET HOOK. FROM BUITENZORG. JAVA.
FURNISHES SECOND GRADE GUTTA PERCHA.

Fig. 4— leaves OF PALAQUIUM TREUBII BURCK, GROWN AT BUITENZORG, JAVA. FURNISHES
SECOND GRADE GUTTA PERCHA.

S^{^;:; rUSRA OF THE PHILIPPINES

Fig. 5.— PALAQUIUM LATIFOLIUM BLANCO. PROVINCE OF TAYABAS, LUZON.

"i^'iit^'^;,!-:^

Mt^^'^^'S^^^

Fig. 6— PALAQUIUM BARNESI MERRILL. ISLAND OF MASBATE.

' FLORA OF THE PMlUPPtNES. ■

y^ai^^, ?j*vH^«j^, fhUurl^^<^

Fig. 7.— PALAQUIUM AHERNIANUM MERRILL. TUCURAN, DISTRICT OF ZAMBOANGA, MINDANAO.

'^i0^S^-^^i^'^':::^n"

- - ■•^■■' ■ -"■^. - ■ - ' ■ ^ ■ ^v>. ^^i^^%e-i'^^ t-^J^^Vi^H^ afei.f€ I • ■ ■ ^.,. vr^-.-

FiG. 8 .— PALAQUIUM CELEBICUM BURCK. DISTRICT OF COTTABATO, MINDANAO.

^^Lit^cLi^^i .... t*a."vuti^t^i: ^'^h^,

Fig. 9.— PALAQUIUM LANCEOLATUM BLANCO. PROVINCE OF TAYABAS, LUZON.

Fig. 10.— PALAQUIUM GIGANTIFOLIUM MERRILL. PROVINCE OF TAYABAS, LUZON.

:^^•■■'^■5■«■^lfe

Fig. 11— PALAQUIUM LUZONIENSE (F. VILL.) VIDAL. PROVINCE OF TAYABAS, LUZON.

FiQ. 12.— PALAQUIUM MINDANAENSE MERRILL. DISTRICT OF COTTABATO, MINDANAO.

I« tf MMtmMMT UW«M»0«WI

' iji7l\

' PtOfiA OP THE PHticlPPINtS.

Fig. 13— PAYENA LEERII (T. ET B.) BENTH. ET HOOK. TAWI-TAWI.

M/>V

Of

Vc^

MAP No. 1.

iiiination of them made, which resulted in giving to the tree the
name of Dichopsis gutta Benth et Hook, fils. A few years later
the Dutch botanist, Burck, pointed out the fact that as early as
1837 Padre Blanco (5) had given the name of Palaquium to this
genus of Sa\potace{p, and accordingly most botanists have adopted
the generic name Palaquium for these wonderful species^ of forest
trees which produce the bulk of all the gutta percha of commerce.

As the demand for gutta increased and the trees of the species
Pal. gutta became scarcer and more difficult to reach, the native
collectors were not slow in finding other species that produced
gutta percha, though of an inferior quality. Among these Pal.
treuhii Burck, Payena leerii Benth. et Hook, tils, and Mimusops
halata Gaertner, fils, are the best known. Many other species have
been found in Sumatra, Borneo, Celebes, and the Malay Peninsula,
but what part they play in the production of the gutta percha of
commerce has not yet been determined.

The accompanying figures will show some of the resemblances
and differences between the species above mentioned. The trees
of the genus Palaquium are among the largest of the tropical forest
and are generally to be noted by the brilliant green color of their
leaves above and the golden to copper-brown shimmer below.

The following general description of the botanical characteris-
tics of Palaquium is made by Mr. Merrill:

PALAQUIUM, BLANCO 1837 (dICHOPSIS THWAITES).

Usually large trees with rusty-tomentose 'branchlets. Leaves obo-
vate or oblong, acute or obtuse, petioled, coriaceous, glabrous beneath,
or densely rusty-tomentose. Flowers fascicled, axillary on the
naked branches below the terminal leaves. Calyx lobes 6, in two
series, corolla lobes 6. Stamens 12 to 18, attached near the base
of the corolla. Ovary 6-celled. Fruit fleshy, ellipsoid or ovoid,
1 to 2 seeded. Seeds exalbuminous, cotyledons large, fleshy.

In regard to the species Mimusops halata mentioned above, it

^ Of late years the Dutch and English botanists in the Orient have been
inclined to divide Pal. gutta, the most valuable of the gutta percha pro-
ducing species, into three species, viz. Pal. gutta, Pal. ohlongifolium, and
Pal. horneense, but as no certainty of differentiation yet exists, while the
gutta percha from all is the same, they may for the present be all classed
under Pal. gutta.

10

is to be noted that it is the only representative so far known of
gutta percha producing trees in the Western Hemisphere. It was
discovered in the Guianas in 1857 and contains a fairly good grade
of gutta percha. Obach (6) designates it in his description as a
substitute for gutta percha in all its chemical and physical charac-
teristics. Though of an inferior grade to that coming from Fala-
quium gutta, it may well be classed among the rest of the Palaquium
and Payena species furnishing second and third grade gutta percha.

The gutta percha trees of the Philippines embrace both Pala-
quium and Payena species^ and while their complete determination
or identification is still unfinished^ those which produce the gutta
percha of commerce have been located;, and their final identification
is only a matter of collecting more complete herbarium material.

The following table (No. 1) gives the species at present known.
Those marked (*) probably furnish the largest part of the gutta
percha exported from the southern islands :

Table No. 1. — Present known species of gutta percha.

Species.

Leaves rusty tomen-
tose beneath:
Pal. latifolium
Blanco.

Pal. olelferum
Blanco.

Pal . b a r n e s i i
Merrill.

*Pal. ahernia-
num Merrill.

Leaves glabrous be-
neath:
*Pal. celebi c u m
Burck.

Local name.

Palacpalac or
Alacap.

Alacap or Ba-
racan.

Nato_.

Locality.

Botanical description.

Luzon to Min-
danao.

Calapia-

-do-

Leaves obovate, obtuse, 10 to 30 c. ni.
long, 5 to 15 c. ra. wide; nerves,
i about 15 pairs.

Luzon I Leaves obovate-lanceolate, 10 to 25

cm. long, 6 to 10 c. m, wide, acute;
nerves, about 15 pairs; closely re-
I lated to the preceding,

Masbate j Leaves obovate, obtuse, thin, 12 to 15

c. m. long, 7 to 8 c. m. wide; nerves,
11 pairs.

Mindanao Leaves ovate or obovate, obtuse or

acute, 12 to 14 c. m. long, 5 to 6 c. m.
wide; nerves, 15 pairs.

_do_

Pal. cuneutum i Dulitan_
Vidal.

I

Pal. giganti fo-
lium Merrill. I

Pal. luzoniense ^ Bagalafigit _
Vidal. i

*Pal. mindana-
ense Merrill.

Calapia-

♦PayenaleeriiBenth. do_

and Hook.

_ Leaves lanceolate, acute, 15 to 20 c. m.

long, 5 to 6 c. m. wide; nerves, 12 to

14 pairs.
Luzon Leaves ovate, lanceolate or obovate,

acute or obtuse, 5 to 7 c. m, long. 2

to 3 c. ra. wide; nerves, 11 to 12

pairs; indistinct.

Tayabas Leaves obovate, i50 c. m. long, 20 c. m.

I wide; nerves, 20 to 24 pairs.

Luzon ! Leaves ovate, acute or obtuse, 10 to 14

I c. m. long, 4 to C c. m. wide; nerves,

12 pairs.
Mindanao | Leaves ovate, acute, 9 to 12 c. m.

long, 4 to 5 c. m. wide; petioles '.i

c. m. long; nerves, 14 to 16 pairs.
Tawi-Tawi _— ■ Leaves ovate or ovate oblong, 5 to 10

c. m, long, 2. 5 to 4 c. m. wide, cu-

neate at the base; short acuminate

at the apex.

11

III. GEOGRAPHIC DISTRIBUTION.

As previously stated the first gutta percha trees were reported
from the island of Singapore, and in fact within a few miles of
the city itself. When the substance became a marketable article
these trees were the first to fall and all of the island was soon
devastated. The explorations from Singapore as a center were
made in all directions and with remarkable success. All of the
forest of the southern half of the Malay Peninsula gave large yields,
as well as the islands of the Khio Archipelago, Borneo, and most
of Sumatra. However, from all of the data which have been
gathered from native sources, as well as from the information col-
lected by many Dutch, English, and French explorers, it appears
that the area of distribution of Palaquium gutta is shai^ply
defined. Beyond the sixth degree north on the Malay Peninsula
the trees become scarce or cease altogether; on the northern end
of Sumatra they are likewise lacking. Java, bordering close on
Sumatra, contains none, and Celebes to the east of Borneo has been
found to be equally destitute. Reference to map (Xo. 1) will show
the area of distribution of the Palaquium gutta which is practically
included in a parallelogram inclosing the above-mentioned penin-
sula and islands. This area include some 450,000 square miles
of land, of which only a very small per cent is or ever was covered
by gutta percha trees.

Obach, in his celebrated book on gutta percha, practically limits
the area of gutta percha production for the entire world to this
small territory (7). While this statement is probably true so far
as the gutta percha from Palaquium gutta is concerned, we have
already seen that the area of distribution of the other or inferior
species is extended eastward so as to take in the Philippines, and
the same is also true of Celebes, Java, and the northern half of
the Malay Peninsula.

The number of gutta percha producing species in the Philippines
has already been listed, and some of the localities given where they
liave been found. Attention is again called to the distribution of
these localities, extending so far north as well as south, and it can
be confidently expected that when the forest surveys are completed
nearly all of the islands will be found to contain some species in
more or less abundance. •

12

Owing to the limited extent of the areas where gutta percha trees
have so far been found on most of the islands^ the regions which
produce gutta percha for the market at the present time are con-
fined to the Islands of Mindanao and Tawi-Tawi. The accompany-
ing map (No. 2) is arranged to show the places where gutta percha
species have been found as well as to give some idea of the size of
the districts producing the gutta percha now being exported. The
exact or even approximate extent of these areas is difficult to cal-
culate. Much has not yet been explored^ and the information
derived from the natives is vague and contradictory. The areas
on the map are given conservatively and are known to produce
gutta percha at the present time. Other territories will probably
become known as our intercourse with the wild tribes inhabiting
these regions grows more friendly and open.

TAst of touns and forest regions from which gutta percha is exported to

Singapore.

Central point for col- Point of collection of gutta per-
lection and exporta- ; cha from the various forest
tion of gutta percha. ■ regions.

Name of forest regions from which
gutta percha is collected.

Cottiibato : Tukuran and Dinas Dinas-Subano Camalarang, La-

I bangas, Tukuran.

Malabang ■ Laguna de Lanao, Baras, Lian-

gan, Segayan.

Cldn, Sarangani, and Binang Tagabuli, Manobo, Bilan, Bin-

! ang.

Reina Regente and Salaya j Dama Balao, Matingauanan, Ta-

; layan.

Zamboanga . __ __ Baluan, Curuan, Talucsangi, Pu- '■ Western and northern Subano.

erta Santa Maria. Dapitan, Mi- i
samis.

Jolo (Suhi) _

Transshipped from Davao Cotta-

bato, Zamboanga, or Siassi.

Bongao Siassi, Balambing, Buan, Daja-

patan.

Tawi-Tawi.
Do.

The Islands of Paragua (Palawan) and Balabac were found
destitute of either gutta percha or rubber-producing trees^ although
long and careful search was made for them in many localities.
Owing to their close proximity to Borneo^ and the fact that botan-
ically and geologically these islands are supposed to be more closely
allied to Borneo than to the rest of the Philippines^ it was confi-
dently expected that both gutta percha and rubber would be found
there. The absence of these forest products is probably due to
the uneven distribution of the rainfall with a long drought in
January, February, and March.

■^^^^^H

Ifetf^ >v';*?!*W#tH«;

■kiS-!^^M&

^^^^^^H^^H^HQrana^nns|^^s^H

■"^ •^^''^^'•'^^sS^^

Fig. 14.

-GUTTA PERCHA LEAF (PALAQUiUM GUTTA) ENLARGED, SHOWING THE FIBERS OF
GUTTA PERCHA PERMEATING THE LEAF INTERIOR.

Fig. 15 —ready TO FELL A LARGE GUTTA PERCHA TREE FOR EXPERIMENTAL PURPOSES.
DISTRICT OF ZAMBOANGA, MINDANAO.

Fig. 18.— a GUTTA PERCHA TREE FELLED AND RINGED BY THE SUBANOS NEAR CURUAN, DIS-
TRICT OF ZAMBOANGA, MINDANAO.

13

IV. METHODS OF COLLECTING AND MARKETING.

(a) COLLECTING.

The question of what is the best method for collecting gutta
percha has troubled owners and dealers from the beginning, and
a satisfactory answer is still lacking. The trees are in the tropical
forest regions of the Malay Archipelago, Borneo, and the Philip-
pines, which are inhabited by the wildest pagan tribes only. These
natives are the natural gutta percha collectors and as a matter of
fact have done all the collecting since the beginning. They evolved
a method which answered their requirements very satisfactorily.
As might be inferred, they wished the maximum yield of gutta
percha from each tree with the minimum expenditure of work or
time. That the method was extremely wasteful did not concern
them nor were they bothered over the prospect of a bankrupt
future.

The method, which is still in vogue from the westernmost part
of Sumatra to the easternmost point of Mindanao, is, with various
minor modifications, practically as follows : The tree is first cut
down and the larger branches at once lopped off, the collectors say
to prevent the gutta percha milk from flowing back into the small
branches and leaves. As has been previously stated the milk or
latex is contained in the inner layers of the bark and leaves, in
small capillary tubes or ducts. (See fig. 14.) To open these so
as to permit the maximum amount of the milk to escape, the
natives cut rings in the bark about two feet apart along the entirv3
length of the trunk. The milk as it flows out is collected in gourds,
cocoanut shells, large leaves, or in some districts in the chopped-
up bark itself, which is left adhering to the tree for the purpose
of acting as a sort of sponge. (See fig. 16.) After one or two
hours, when the milk has c-eased to flow, the contents of the recep-
tacles are united and boiled over a fire for the purpose of finishing
the partial coagulation. The warm, soft mass is then worked with
cold water until a considerable amount of the liquid is mechan-
ically inclosed. To further increase the weight, chopped bark,
stones, etc., are added and the whole mass worked into the required
shape with most of the dirt on the inside.

The gutta percha gathered in this way well repays the amount
of work expended. The two vital defects of the method are —

(1) The method is very wasteful, the yield from each tree being

J4

a small proportion to the total amount. What this per cent
is has been investigated by scientists with the result that the
figures differ widely. Remembering that the gutta percha milk is
contained in capillary ducts and tubes^ it will be seen that a con-
siderable amount can not flow out on account of capillary attraction,
no matter how much cutting is done. It very seldom happens also
that a tree falls in such a way that all its trunk is exposed so as
to admit of ringing on all sides. As a general thing from one-third
to one-half of it is inaccessible to the process of ringing, and all
the milk within this portion is consequently lost. Even the larger
limbs are not deemed worth ringing and consequently all the milk
in them and in the leaves also goes to waste ; to this must be added
the considerable quantity spilled on the ground through carelessness
and lack of enough receptacles for every cut or bruise from which
the milk flows. (See fig. 19.) *

The method employed to find what percentage of gutta percha
has been removed from a tree by the native collectors was to deter-
mine the per cent of gutta percha remaining in a given area of
the bark, multiplying this by the total bark area of the tree and add-
ing 15 per cent of this amount for that contained in the bark of the
branches and in the leaves.

The amount which the native collectors secure from the average
full-grown tree apparently varies according to the species, season,
personnel of collectors, etc. Most authorities place the amount per
tree at one-fourth of a pound. The director of the botanical garden
in Penang (8) secured 1| pounds of clear gutta percha from a
large tree {Pal. gutta) estimated to be 60 years old. Wray (9)
obtained somewhat over 2 pounds from a Palaquium gutta tree at
least 100 years old, and 2| pounds from one of an inferior species.

Burck (10) made some extended experiments in Sumatra and
st^cured an average of less than 1 pound from full-grown trees,
while Serullas (11) in Sumatra obtained almost 1 pound from a
giant tree. Trees of inferior grade have been found to give as
high as 8 pounds. Probably the best average obtainable is 3 pounds.
Tn the Tiruray District of Mindanao I secured 1 pound of clean
gutta percha from a tree 135 feet high and 5 feet 4- inches in cir-
cumference at the base. The work was carefully done by the natives.
Taking a measured amount of the bark of this tree after no more
gutta percha could be collected by the native method, and extracting
all of tlie gutta percha which it still contained, it was estimated that

19.— A GUTTA PERCHA TREE TAPPED IN SUCH A MANNER THAT THE FLOWING MILK IS
NOT ALL ABSORBED BY THE CHOPPED-UP BARK, BUT MUCH OF IT IS LOST ON THE
GROUND BELOW. TUCURAN, DISTRICT OF 2AMB0ANGA, MINDANAO.

FlQ. 20— A LARGE GUTTA PERCHA TREE FELLED AND RINGED. NO OTHER GUTTA P£RCHA

TREES WERE FOUND GROWING WITHIN A LARGE RADIUS, AND NO SAPLINGS WERE

OBSERVED. DISTRICT OF ZAMBOANGA, MINDANAO.

Fig. 21.— stem OF GUTTA PERCHA TREE, SHOWING SCAFFOLDING ERECTED BY SUBANOS FOR

THE PURPOSE OF FELLING THE TREE. SOME ROOTS WERE STILL ALIVE, BUT NO

STOOLING WAS APPARENT. DISTRICT OF ZAMBOANGA, MINDANAO.

Fig. 22.— a CHINESE MORO TRADING BOAT STOPPING AT PARANG PARANG, MINDANAO, FOR THE
PURPOSE OF BUYING GUTTA PERCHA AND TAKING IT TO COTTABATO FOR EXPORTATION.

15

after collection there still remained 6^ pounds of gutta percha.
Taking into consideration the fact that had the tree not fallen in
such a way as to leave almost all of the trunk propped high enougli
above the groimd to allow the milk to be extracted from the bark
on the under side, the amount extracted would undoubtedly have
been much less, or in other words ten times more gutta percha
would have been left to rot with the tree than was taken from it
by the natives. Other investigators have secured figures as large
as these and some found that forty times more gutta percha was
left behind than was secured by the careless collectors.

(2) It leaves the future unprovided for. It has been seen that
the invariable practice of the native collectors is to fell the tree
in order to extract the gutta percha. (See fig. 20.) In some cases
it has been reported that the stumps stool afterwards, and in course
of time produce new trees, but it can be safely asserted that this
is the exception and not the rule. Of those I have found cut down
in the Philippines, none have ever stooled, though in one case I
saw some of the roots of the stump alive long after the felled tree
was well advanced toward decay. (See fig. 21.)

It is fortunate that only the full-grown trees contain enough
gutta percha to repay the work of felling, ringing, etc.; otherwise
the complete extermination of the gutta percha forest would only
be a matter of a year or so. On the other hand the felling of all
the trees old enough to bear seed works to the same end with a
somewhat longer time limit.

(b) MARKETING.

Having been collected and put in marketable shape, the gutta
percha is carried in baskets on the back of the collectors to the
nearest waterway and thence by boat (see fig. 22) to the most
accessible town, where, applying the description to the Philippines,
it is exchanged for barter to some Moro, Chinese, or Filipino mer-
chant (comerciante) living there for the purpose of dealing in all
kinds of native products. From here it is shipped to one of the
ports doing an export trade with Borneo and Singapore. The
entire gutta percha trade is practically in the hands of the Chinese
in the latter city, and they guard the secrets of boiling, working
over, mixing, adulterating, and coloring the gutta percha for Euro-
pean markets most zealously. All who have tried to investigate
their methods agree that there is no connection between the various

16

grades and the different tree species^ and that pure gutta percha
from the species Polaquium gutta is no longer found on the market
unmixed with inferior grades.

Strangely enough, I was unable to find in Singapore any statis-
tics regarding the importation of Philippine gutta percha. The
Chinese dealers denied receiving any, and beyond a few piculs noted
in the annual import statistics, no mention of it was found any-
where. I afterwards ascertained that the gutta percha first goes
to Sandakan and Labuan, in British North Borneo, and is there
transshipped to Singapore, entering as North Borneo gutta percha.

Unfortunately the amount collected for exportation can not be
given with any degree of accuracy, as the export statistics (12)
include gutta percha with all other gums. It is known, however,
that the amount reaches into tens of thousands of pounds.

V. LAWS REGULATING COLLECTING AND SHIPPING.

Considering the almost lawless w*ay in which gutta percha is
collected and marketed, it is pertinent to review briefly the few
steps taken toward legislating on the subject. The English long
ago realized that the gutta percha forests of the Malay Peninsula
were doomed to destruction unless radical measures were taken to
change the method of collecting. The first law passed was to pro-
liibit the felling of trees in order to collect the gutta percha. As
the law never penetrated to the wild tribes of the interior where
the collecting was done, it was not effective. As a surer method of
stopping the destruction, a second law was passed which prohibited
the exportation of gutta percha from coast towns in the Federated
Malay States in which the English could, of course, exercise per-
sonal supervision. The result was that the exportation from those
places ceased promptly, but the felling of trees did not stop, the
export simply traveling northw^ard by overland routes until it was
outside of English jurisdiction, and from there it was shipped to
Singapore. I can not find that anything effectual has been accom-
plished by the English or by the Dutch authorities in Sumatra
and Borneo toward remedying the difficulty. It seems to be gen-
erally realized at last that wild natives can not be prohibited from
doing things where there is no law nor show of authority. Cer-
tainly they will not cease felling gutta percha trees until some one
can show them an easier method for collecting the same amount
or more of the material, so long as gutta percha has a market value.

17

The English had the true idea when they took away its market
value through prohibiting exportation. The only trouble was that
the Malay States are on a peninsula and not an island. This law,
if applied to the Philippines, might succeed better by reason of
their geographical situation, but so far nothing of this kind has
been tried here. As soon as the Forestry Bureau was established
in 1899, the felling of gutta percha trees was prohibited (13).
Eules and regulations were provided for tapping the bark of the
tree with a bolo in such a manner as to allow the milk to be secured
without killing the tree. As the amount of gutta percha obtained
by this process was much less than that secured from felling the
tree, while the labor was fully as great and was dangerous besides
(some trees being 70 feet to the first limb) the wild natives never
practiced this method, nor did they ever hear of it, and all the
gutta percha so far exported has been at the expense of so many
trees killed.

Islands such as Mindanao and Tawi-Tawi can not stand this
for any length of time and already the gutta percha trees have
entirely disappeared from the vicinity of the coast regions and of
the large rivers. According to the forest surveys made so far in
the Islands the average number of trees of 1 foot in diameter is
between forty and fifty per acre, and considering the large number
of species found in the forests the number of trees of any one
species is generally placed at four or five. With this liberal allow-
ance the forest acreage of the southern islands will probably supply
gutta percha at the present rate of cutting for three or four years
longer, but not for more than that.

It must not be supposed that scientific investigation has not been
directed toward solving this vexed question of securing gutta percha
in paying quantities without killing the trees, but before describing
the results of this work, the chemical and physical characteristics
of gutta percha as well as the prices to be realized for it must be
considered in order to demonstrate the difficulties to be overcome.

VI. GRADES AND PRICES.

The prices governing the sales of all grades and kinds of gutta
percha in Singapore, the chief market of the world, seem to be most
arbitrary and uncertain. As a general thing they have increased
continuously and steadily since the beginning of the industry.

8766 2

18

Formerly the different grades of gutta percha were named from
the well-known districts or shipping ports from which they came.
An attempt was also made to designate the species of tree furnish-
ing the product^ and a further distinction was given as to quality.
For instance "Koatei guta merah No. 1^^ was first grade of gutta
percha from Palaquium gutta coming from Koatei^ while ^Tahang
white soondi No. V was first-grade gutta percha from Payena leerii
from the Pahang district.

These names and gradings are still kept up as a matter of con-
venience for cable codes^ etc., hut the significance of the names is
almost entirely lost, certainly as far as any indication of the tree
species is concerned, and often as regards the district of production
as well. The Philippine gutta percha for example has neither grad-
ing nor price in Singapore, and probably comes in under Sarawak
white, red, etc.

As has been stated previously, the secrets governing the selection
boiling, adulteration, coloring, etc., of the various grades are closed
and known to the Chinese exclusively. This is also true in the
Philippines, though very little except boiling and cleaning is at-
tempted before shipping to Sandakan.

Most of the Philippine gutta percha passes through three hands
and the rise in price is quick and decided. My experiences in the
gutta percha districts of Mindanao and Tawi-Tawi were to the
effect that the wild native collector had to take about what he could
get, which was on an average of $10, Mexican, for a picul of 162^
pounds. Money was seldom paid, the usual thing being barter in
rice, cloth, copper wire, cheap jewelry, beads, etc. It is needless to
remark that the middleman realized a good profit on his merchan-
dise. He in turn carried the gutta percha to the export towns and
sold it to the Chinese at the rate of $40 to $80, Mexican, per picul
of 137^ pounds. As this latter amount was the legal weight for
a picul, his profits were increased by the additional pounds which
he deliberately stole from the ignorant natives. The Chinese ex-
porter pays $5 to $7, Mexican, per picul forestry dues (he being
the only one of the three with a fixed residence and amenable to
Forestry regulations) and exports the gutta percha to Sandakan or
Singapore, where it probably brings $100 to $150, Mexican, per
picul of 133^ pounds. There is no definite information on this
subject, however, as Philippine gutta percha, as has been stated,
is neither rated nor graded in Singapore, k year and a half ago

19

when the best grade of gutta percha in the Philippines was said by
the Chinese of Cottabato to be worth $80 per picnl, the following
analyses of Singapore gntta perchas were made by Van Eombnrgh
and Tromp de Haas (14) :

Grade.

Bila (red) soondi _^

Sarawak soondi No. 2

Penang gutta Palelo No. 1--
Sarawak red soondi No. 1— .
Bagan white soondi No. !__-

Koatei guta merah No. 2

Indragiri white soondi

Sambas white soondi

Koatei guta merah No. 1

Pahang white soondi No. 1 .

P.ct
33.6
37.1

2.1
19.0

0.7
21.7

2.0

1.0
14.8

4.2

Water.

Resins.

Gutta.

P.ct.

P.ct.

P.ct.

7.0

31.4

28.0

6.8

25.5

29.6

5.8

53.8

38.3

3.9

35.5

41.6

8.6

36.5

54.2

5.1

28.5

44.7

4.1

46.2

47.7

4.4

53.6

41.0

3.8

34.8

46.6

0.5

12.8

82.5

Price

per

picul.i

$150
135
180
350
350
360
370
380
500
500

1 Mexican currency.

According to these analyses the best grades of Philippine gutta
percha may well rank with any of the first four on the list^ espe-
cially as my chemical and physical tests show the high grade of
the gutta in them.

Another example of the difficulty in dealing with the Chinese
gutta percha merchants in Singapore is the experience of an Amer-
ican merchant of Manila, who, about this time, took a considerable
quantity of the best grade of gutta percha from Mindanao over to
Singapore by way of speculation. He was only offered $8 per picul
by the leading merchants there, and it was not until they found
out he was not anxious to sell at all but would ship the product
to America, that they finally closed with him at $70 per picul.
How much the gutta percha was really worth he never found out.

The evidence then all goes to show that the price of Philippine
gutta percha jumps from about $8 a picul in the mountains where
it is gathered by the wild tribes, to $150 in Singapore. Thus the
native collectors get almost nothing, the Government about as much,
and the Chinese the rest. The Chinese might possibly get even
higher prices by exporting direct to London or America, though
apparently that has not yet been tried.

It is stated on good authority that the Chinese in all their
manipulations for preparing the gutta percha for the European
market go solely by smell, color, toughness, and the softening and
hardening test in hot, then cold, water. At any rate they are cer-
tainly very skillful in the work, although careful inspection of the

20

above table^ as Van Eomburgh points out, would tend to show that
their prices were not at all warranted by the analyses. So long as
the collecting of the gutta percha is all in the hands of wild natives
and the manipulating and marketing controlled by the Chinese,
we can not hope to have the gutta percha trade on a fair business
basis. However, as the supply steadily decreases while the demand
and prices increase, the attention of Governments and manufac-
turers will more than ever before be directed to the subject and
perhaps the hoped-for relief will come through scientific propaga-
tion of gutta percha trees and scientific collecting of the gutta
percha.

VII. CHEMICAL PROPERTIES.

A chemical examination of the milk or latex above referred to
as coming from the gutta percha trees upon wounding the bark
shows it to be composed of an emulsion of water and oil in a
finely divided state. According to the species of tree the water
varies from a small (best species) to a very large percentage (poor
species). A drop of the milk caught on the finger undergoes no ap-
parent change for a few minutes^ but by the end of this time a thin
rubbery scum can be observed to have formed on the surface. If
this be removed a second film will form, and so on until the entire
drop has become a small piece of a tough, leathery substance. When
a fresh drop is worked between the fingers the hardening process
or coagulation takes place very quickly, and by boiling or adding
certain chemicals, such as mineral or vegetable acids, alum, salt,
etc., it takes place almost instantaneously. What the nature of
this hardening process is, appears to be unknown. The subject will
be investigated in this laboratory.

After coagulation sets in (see below), the oily portion becomes
hard and tough while most of the water separates or is inclosed
mechanically. Subjecting this hard and tough mass, taken for
example from the Palaquium gutta species, to further examination,
it proves to be insoluble in water and very stable against the action
of either dilute acids or alkalies. In chloroform or carbon bisul-
phide it is easily soluble, while ether, petroleum ether, and alcohol
dissolve it only in part. By subjecting it to the action of cold
alcohol, a yellow amorphous resinous powder can be extracted. Hot
alcohol further extracts a white crystalline resin, leaving a tough
horn-like residue, which is easily soluble in chloroform and carbon
bisulphide and can be precipitated from these solutions by alcohol

21

as a white flocculent mass, which by warming or through pressure
quickly returns to its original appearance. Taking the three con-
stituents of gutta percha in the order described above, the names
Fluavil, Alban, and Gutta were given them by Payen (15) in 1852.
Besides these constituents, all gutta percha was found to contain
more or less dirt, coloring matter, and water inclosed mechanically.

Table No. 2. — Analyses of representative samples of gutta percha from Singapore
and Philippine markets, as well as from different species of gutta percha trees, ta
shoiv composition and comparisons.

Source of specimen.

1. Co 1 1 e c t e d from Pal.

gutta trees in exper-
iment garden, Bui-
tenzorg, Java.

2. Sample analysis of pro-

duct of Pal. gutta
made by Van Rom-
burgh.

3. Product from two trees

of Pal. leerii, Tawi-
Tawi.

4. Product from tree of

Pal. mindanfense; in
mountains southeast
of Cottabato.
5 Brought into Cotta-
bato by Moros from
Subano region,
northwest of Tucu-
ran.

6. Purchased from Moros

at Bongao.

7. Product from tree of

Pal. celebicum; in
mountains southeast
of Cottabato.

8. Brought into Cottaba-

to by Moros from Bi-
nang region; botani-
cal origin unknown.

9. Product from un-

known species; in
mountains southeast
of Cottabato.
10. Product from Pal.
ahernianum; in
mountains north of
Tucuran, Mindanao,

Appearance.

Gutta, Resins.

Close, compact,
tough, whitish
to pink and
brown.

White, somewhat
elastic, very
tough, !

Somewhat tough, i
white, pinkish, |
and browm. j

Clean, pinkish :
balls; tough. I

Tough, compact
slab.

Inclined to crum-
ble; white to
brownish.

Long coils on piece

of bamboo;

dirty and dark

colored.
Dark brown, hard,

and crumbling.

Heavy, compact
mass, crumbling
easily; light red-
dish brown.

Per ct.

74,77

Per ct.
20,74

85.15 ! 11,02

48,19 41,38

38.42 i 49,08

32.49 r>4,08 ■

Water.

Per ct.
2.49

Dirt.

Perct.
1.99

Grade.

28.37
31.30

37.42

51, 86

18,32
.04

30.20 i 57.40 I

23.64 ; 53.99 I 13,87

24.55 ; 43.21 I 15.19

15. 83
16.79

.60

Superior,
but not
on Sing-
a p o r e
market.
Do.

Superior
in Phil-
ippines.i

First,

Second.
Do.

8.48 Third.

17.04 I Fourth.

i

1 The grading of the Philippine gutta percha is done by the Chinese exporters.

The method adopted for making the above analyses is a modifi-
cation of those used by Obach (16) and Van Eomburgh. The
former determined first the per cent of water by drying a weighed
sample to constant weight on a water bath or desiccator, determin-
ing the water by difference. The resins were then extracted with
ether and weighed after the solvent had been completely evaporated.

22

The gutta and dirt were thus left and were separated by chloroform,
which dissolved the gutta, leaving the dirt to be filtered, dried, and
weighed. The chloroform was then evaporated and the gutta
weighed.

Van Komburgh (17) in his latest analytical work uses the fol-
lowing scheme: The weighed and finely divided substance is dried
to constant weight in an atmosphere of dry carbondioxide gas, which
fulfills the double purpose of drying and at the same time prevent-
ing oxidation. The sample is then dissolved in hot chloroform,
thus, allowing the undissolved dirt to be filtered off, washed, dried,
and weighed. The chloroform solution containing the gutta and
resins in diluted with chloroform to 100 c. c. and an aliquot portion
taken, evaporated, and dried to constant weight as above. By
extracting the residue with hot alcohol or acetone the resins are
removed, when the remaining gutta is dried and weighed. The
resins are then estimated by difference. Van Eomburgh points out
that the largest source of error in using this method is due to the
evaporation of the chloroform. To avoid this loss and save time
the following modifications were adopted by me:

DIRT.

A fair sample of the gutta percha to be analyzed was finely
divided and quartered down to a small amount. Of this 0.3 to 0.5
gram was taken in a weighed thimble filter and extracted hot in
a Soxhlett apparatus, chloroform being used as the solvent. When
all was dissolved but the dirt the latter was dried on the filter and
weighed.

RESINS AND GUTTA.

The chloroform solution is then evaporated to dryness in the
flask (previously tared) attached to the extractor and dried to
constant weight on the water bath in a stream of dry carbon dioxide
gas. After weighing, the contents are extracted with hot alcohol or
acetone, when the flask is again dried as before and weighed. The
loss in weight equals the weight of resins and gain of the flask the
weight of gutta. The water is estimated by difference.

Analyses of samples taken from several trees of one species show
the percentages of the constituents to vary considerably, they being
influenced, probably, by the age of the tree, the conditions of its
growth (soil, moisture, shade, etc.), as well as by the season at
which the sample was taken. For illustration of this, two analyses

23

of gutta percha known to have been taken from different trees of
Palaquium gutta are given to show the large variation in the per-
centage of gutta. It must, therefore, be understood that the figures
obtained from the analyses of the gutta percha taken from any one
tree will not necessarily represent the exact values for that species.
An average from a number of trees is necessary to secure true
values. In the same way, samples from any commercial grade of
gutta percha may vary quite a little in their percentage composi-
tion, the differences, however, generally falling within a well-defined
limit.

The ^^dirt^^ foimd in all commercial gutta percha, as has been
stated, may be there unintentionally, or have been added with intent
to defraud. In either case it generally consists of finely chopped
bark, leaves, small sticks, etc. From 2 to 6 per cent of dirt is not
only admissible but generally unavoidable, while more than that
is looked upon with suspicion. So intimately is some of the dirt
mixed with the gutta percha that even the best machines fail to
eliminate the last one or two per cent.

A certain amount of coloring matter which exudes from the bark
when it is cut is also mixed with the gutta percha milk and colors
the resulting product. Certain species give a distinctive color to the
material taken from them, so it has become a practice of the Chinese
in Singapore to boil inferior grades with the bark of the best species
in order to give them the correct color.

Under "resins'^ are considered the resinous-like substances which
with gutta go to form the substance gutta percha. These resins
vary greatly in appearance. In gutta percha from Palaquium gutta
for example, as has already been stated, one is a white crystalline
mass while the other a yellow amorphous powder. In other species
they may be oily or brittle, colored or white. Judging from the
formulas C^oH^gO and (CjoH,P)^ which have been given to alban
and fluavil respectively, it might be inferred that these resins are
oxidation of products of gutta (CjoHjg)^. Sufficient work has not
yet been done on these bodies, however, to make this anything more
than conjecture.

Again taking the gutta percha from Palaquium gutta, for illus-
tration, it is found that the 10 to 20 per cent of resins which it
contains is not a detriment but rather a decided advantage. Besides
adding much to the bulk, these substances are insoluble in water,
poor conductors of electricity and quite stable against the action of

24

air and moisture. In fact, gutta percha at present prepared for the
insulation of submarine cabfes is composed of one part of resins to
every two parts of gutta. When the amount of resin passes this per-
centage, however, the toughness of the gutta percha is lessened and
other objectionable qualities become apparent. The necessity, then,
of knowing the percentage of resin in a given quality of gutta
percha before using it for manufacturing purposes is plainly
apparent.

As might be inferred from the preceding, the '^gutta^^ is the
principal constituent in gutta percha. The methods of separating
it from the other constituents have been given and its indifference
toward dilute acids and alkalies noted. Concentrated nitric acid
causes violent oxidation while sulphuric acid carbonizes it in a
short time. Alkalies, even when concentrated, have practically no
action on it. The best solvents for gutta are chloroform, carbon
bisulphide, and carbon tetrachloride. From all of these solutions
it may be reprecipitated by the addition of alcohol.

If gutta be subjected to dry distillation isopren CgHg and
kautchin CioHj^ (18) distill over as the chief decomposition
products, and are identical with the isopren and kautchin (19)
recovered from the dry distillation of rubber. Tilden (20) suc-
ceeded in changing isopren back again into a rubber-like substance
through the action of concentrated hydrochloric acid. Isopren,
according to Ipatiew and Wittorf (21), is methly divinyl CH2=C
(CH..) — CH=CH2, so that both gutta and rubber will perhaps be
found to be polimerization products of isopren.

The discussion has so far been of the gutta found in the species
Palaquium gutta. Dr. Eugene Obach (22), as chemist for a large
cable insulating company, made analyses of specimens of gutta
percha from different species of trees as well as from many grades
of commercial gutta percha. In his table of analyses he puts under
the name of "gutta^^ the substance found in each sample, which
was insoluble in boiling alcohol but soluble in chloroform. The
"guttas^^ thus found were variously colored from white to dark
brown, and possessed different tensile strength, from "elastic'^ and
"very strong^^ to "brittle.^^ Obach thus used certain slight chemical
similarities as his Criterion of a gutta and neglected, apparently,
the wide physical differences, which, as will be shown later, these
bodies display. Provided there are many kinds of guttas, it is
easily understood why a chemical analysis alone of a gutta percha

25

will give almost no insight into its value unless accompanied by
physical tests of the gutta contained in it.

VIII. PHYSICAL TESTS OF GUTTA.

Before going further with the discussion as to whether chemical
or physical tests should decide what is or is not '^^utta/^ attention
is called to the various physical properties of these bodies. To
provide material for these physical tests^ they were isolated in
considerable quantities from various representative Singapore and
Philippine gutta perchas by means of solvents, and after evapora-
tion were dried in a stream of dry carbondioxide gas to prevent
any possible oxidation. When heated to the temperature" of boiling
water they could be easily cut or molded into the necessary shape
for performing the following experiments :

GuttH

No.
No.
No.
No.
No.

Color.

Action toward light.

j i Rotation

I Refractive ^ in 0.5 per
index. cent

■ solution.

Light brown

Cream white

Yellowish white \

Very light chocolate _

10 : Cream white

70° a

1. 5093
1.5088 "
1 5089
1.5093
1.5076

Heat, I

soft- \ Stress,
ening tensile
tem- 1 strength
pera- |( pounds),
ture.

0.75
6.50 '
7.50 i
6.50 '
4.75 i

62

60 i

61 !
61 i
56 '

Sq. inch.
5262. 4
6668. 15
5134. 7
6451.45

0)

^ Brittle. (The numbers in this table refer to Table No. 2.)
EXPLANATION OF TABLE.^

The ^^color^^ of the guttas undoubtedly comes from the bark of
the tree when cut to secure the gutta percha, for, by repeated solu-
tion and precipitation^ the color may be almost entirely eliminated,
leaving the gutta only slightly tinted from a cream color to light
pink, and pure white when finely divided. It is my opinion that
all variations of color are only incidental and not connected with
the chemical structure of the gutta itself. The amount of color
in the above samples was a minimum and not sufficient to have any
material effect on the physical properties. The experiments

^ The results given in this table and some of the explanations appeared in
the previous annual report of the Superintendent of Government Labora-
tories, but as subsequent experience and the completion of botanical data
has led me to take up the subject from a different standpoint, they are again
appended for the sake of completeness.

26

with light, namely, those given under refractive index and rotation
are employed with great success in the commercial analysis of
sugars, oils, fats, butters, etc. This is due to the fact that each
chemical individual, providing it is capable of transmitting light,
has an index of refraction peculiar to itself, which, for purposes
of comparison, must be taken under constant conditions and, pro-
vided it is able to rotate the plane of polarized light, a degree of
rotation which is also constant. While two chemical individuals
may show identity in some one physical property, they can not
continue this identity in two or more, so that more than one method
was necessary to determine the relationship of the guttas examined
by me. Substitution, adulteration, or variation in chemical struc-
ture can in this way be easily discovered and determined. Owing to
certain mechanical and chemical difficulties encountered in making
these determinations on the guttas, the limits of error of experi-
mentation are outside of the differences found between Nos. 1, 3,
4, and 5, but do not include the marked difference displayed by
No. 10. In determining the refractive index, an Abbe-Zeiss refrac-
tometer was employed, a small amount of a concentrated solution
of pure gutta in chloroform placed on each of the prisms and
allowed to stand until the odor of chloroform had entirely disap-
peared. The prisms were then closed, and kept at a temperature of
70° C. until the readings became constant, showing that all chloro-
form had evaporated. The above figures are the results of many
determinations made with carefully prepared samples.

The rotation was determined in chloroform, 0.5 per cent solution
being used, because, when more concentrated, the absorption of
light was too great to admit of accurate readings.

The physical tests given in the above tables are so diversified
as to bring out clearly the extent of resemblance between the various
samples of gutta submitted to them. The results show little varia-
tion between Nos. 1, 3, 4, and 5. Indeed, these samples may be
regarded as practically identical in composition. The physical
constants appear to be those of a single chemical individual, the
refractive index varies only in the third decimal place, the rotation
is the same within the limits of only 1°, and the softening points
vary only from 60° to 62°. The small amount of resins in the
specimens, which it was impossible to remove, would be sufficient
to account for even greater variations. 'No. 1, however, is the best
sample,. used for a standard and taken from Dichopsis gutta; Nos.

27

3, 4^ and 5 are from the Philippine Islands. It would appear from
this that gutta is a chemical individual^ identical in all cases, and
any substance, such as No. 10, for example, which varies from the
properties recorded above, should not be designated as such. This
opinion is, however, advanced, subject to further confirmation by
extended chemical investigation looking toward the deterinination
of the chemical constitution of gutta. In the case of sample No.
10 the substance designated as gutta, and the real gutta of No. 3
are very similar in appearance and chemical behavior. In tensile
strength, however, they are widely divergent, and this difference
is accentuated and not lessened by the other ph^^sical tests, for
while these latter differences are not so marked, yet they clearly
show that all the physical constants of No. 10 differ more or less
from all the others, and hence this substance must certainly be
different in chemical constitution.

The action of heat in softening gutta perch a and making it
plastic has previously been used as a test of value. It has been
found that the best grades require a higher temperature to soften
them than the lower grades. According to the results obtained by
me, the inferior grade of gutta (No. 10) also possesses the property
of softening at a lower temperature than the superior gutta. The
softening point was determined by molding a piece of gutta into
the bottom of a glass tube sealed below, placing a sharp pointed
glass rod in contact with the surface, and gradually heating in a
bath of sulphuric acid until the point of the glass rod just began
to enter the gutta.

The tensile strength, or toughness, possessed by gutta, next to
its resistance to sea water is undoubtedly its greatest merit com-
mercially. Even the inferior grades of gutta percha are used for
objects requiring toughness combined with pliability and strength.
In the insulation of a submarine cable great toughness is imperative,
for during the laying of the cable it is constantly subjected to great
strains from kinking, pulling, rubbing, etc., and when it has reached
to the ocean bottom where the pressure is often three and a half
tons to the square inch, it must not have sustained a fracture even
as large as the diameter of a fine hair for otherwise the moisture
would slowly penetrate to the wires, the insulation would not be
complete, and the cable would have to be pulled up and repaired.

In order that the measurements made might be within the limits
of the instruments at hand, only small strands of gutta could be

28

used for testing. To make these strands free from minute air bub-
bles was well nigh impossible, in consequence of which the breaking
was in most cases brought about by weakness due to this source.
The figures, while thus only approximate, are below and not above
the true values and show clearly the enormous tensile strength of
my samples. Obach (23) gives a tensile strength of 5,000 pounds
for the best gutta percha while for the gutta from it he found about
6,500, which closely corresponds to results given above. This also
brings out most clearly the excellent quality of the best Philippine
gutta percha.

The results of the combined chemical and physical tests on
various samples of so-called "guttas^^ extracted from gutta perchas
of different origin seem to show that the gutta from the gutta
percha of Palaquium gutta has certain well-defined chemical and
physical properties, and they also demonstrate that some so-called
gutta perchas contain a substance which chemically resembles to a
certain extent the above-mentioned guttas, but differs widely from
it in many of its physical properties. As the gutta from the species
Palaquium gutta has stood the test of usage for fifty years, it is only
fair that its chemical and physical constants sliould be used as the
standard of comparison. Until more is known chemically of such
substances as I found in No. 10, a chemical analysis will not be suffi-
cient to determine the value of a gutta percha, but it must be supple-
mented by physical tests. This laboratory will undertake the task of
so determining the chemical properties of gutta and its allied bodies
in the hope of discovering a method of chemical analysis which
alone can be used to determine the value of any gutta percha.

IX. SCIENTIFIC PROPAGATION.

As soon as the native collectors made such heavy inroads on
gutta percha forests as to make certain of their serious decimation
if not entire destruction, the various governments having tropical
possessions in the East began to take note and make inquiries, but
it was not until the last four or five years that the notes became
serious or the inquiries anxious. Both explorations and inquiries
revealed that the greater part of the Malay Peninsula had lost most
of its trees, and that the portions of Sumatra and Borneo which
were still productive were in the most inaccessible mountain forests
of the interior. So thoroughly had the seed-bearing trees been
cleared out of the Malay States tliat a standing reward by govern-

29

ment officials for seeds of the species Palaquium gutta was not
claimed, though the offer stood for a long time. • Van Kombnrgh
(24) in a very extensive tour of Sumatra and Borneo, made for
the purpose of reporting to the Dutch Government the condition
of the gutta percha regions, saw but a few seed-bearing trees, and
these in almost all cases had been protected by native chiefs.

In the botanical gardens of Singapore, Bukit, Tiniah, Penang,
and Buitenzorg, Falaquium gutta trees were growing which had
either been protected from destruction or had been planted for a
sufficient length of time to be seed bearing. These formed the
nucleus of the gutta percha nurseries now being planted by the
English and Dutch governments, with the purpose of obtaining
reliable information as to methods of propagation, the rapidity
of growth, the time necessary for maturing, and above all to furnish
material for testing scientific methods for extracting gutta percha
without killing the trees. Owing to the scarcity of seeds every-
where the government botanists were obliged to resort to various
methods for securing young plants, and their experiments have been
along the following lines :

{a) PLANTING FROM SEEDS.

The fresh seeds are laid in beds of rich earth and allowed to
germinate and grow under partial shade. When about a foot high
they are transplanted to the future plantation, where the soil may
be entirely free from trees, shrubs, or other vegetation (Dutch
method) or where small patches of earth have been cleaned and
loosened for their reception in a forest of secondary growth, heavy
enough only to furnish a light shade (English method). By the
Dutch method a light shade is required around each seedling until
a vigorous growth is secured. The seedlings are set out about
5 by 5 yards apart, though where it is desired to obtain the largest
amount of leaves per acre the space allotted is 4 by 4 yards. No
special care seems necessary except to keep them free from weeds.
Too much stress, however, can not be laid on the care which should
be taken not to break or injure the long tap root of the young plant
during the process of transplanting, for any injury to it stunts the
growth materially or even causes death. Mr. Curtis, director of
the Penang Botanical Gardens, has modified the manner of start-
ing the germination and first growth, by placing each seed in a
separate bamboo joint filled with earth. This joint is made long

30

enough to allow the tap root to strike downwards undisturbed^ and
when the time comes for transplanting it can be transferred^ joint
and all, without any fear of injury, to the place made ready for
it. The bamboo is then cracked open and the plant inserted in
the ground with almost no disturbance of its roots.

The Dutch Government in Java, having many seed-bearing trees,
is now deeply engaged in carrying out a programme which contem-
plates the planting of some 150,000 seeds annually until at least
1,000,000 trees are growing. This will be done on extensive gov-
ernment plantations at Tjipitir, Java. The entire management
is intrusted to Dr. van Eomburgh, director of the Grovernment
Chemical Laboratory at Buitenzorg, who has a corps of assistants
intrusted with testing the gutta percha contained in the seed-pro-
ducing trees in order that none but the best stock may be used.

(h) PLANTING FROM SELF-SOWN SEEDLINGS.

In the forests both of Sumatra and Borneo the natives are still
able to find comparatively large numbers of self-sown seedlings
of the Palaquium gutta species. These, when carefully taken up
and transplanted into air-tight boxes provided with glass covers
and rich earth, can be packed in large numbers in a comparatively
small space and shipped to almost any desired distance. For
instanc-e, 60,000 such seedlings were shipped two years ago from
Southern Borneo to the French Congo, via Antwerp. The plants
transported from Borneo to Singapore in this manner are doing
well in the gardens at the latter place. The Cerman Government
is planning a nursery of such seedlings in its tropical possessions
in New Guinea.

(c) PROPAGATION BY MEANS OF MARCOTTAGE.

As neither direct slipping nor grafting has ever succeeded with
gutta percha trees, the method called marcottage was tried in Java
and the Malay States with some success. This consists in selecting
a young straight limb from a large tree and at the point where
the roots are to grow the bark is removed for the length of an
inch around the entire limb. The denuded spot is then packed
with rich mud, which is held in by a coating of cocoanut or other
fiber. (See fig. 25.) If the mud is kept moist, and only if this
is the case can good results be secured, small roots will generally
appear in three to nine months, when the limb can be cut off and
planted.

Fia. 25.-SHOW,NG THE METHOD CF PROPAGATING GUTTA PERCHA TREES BY MEANS OF
MARCOTTAGE. BUITEN20RG, JAVA.

Fig. 26— a PALAQUIUM GUTTA TREE GROWN IN THE OPEN, SHOWING THE TENDENCY TO
BUSH. BOTANICAL GARDEN, SINGAPORE, STRAITS SETTLEMENTS.

-A TREE OF PALAQUIUM GUTTA JUST TAPPED. THE FLOW OF MILK IS QUICKLY
STOPPED BY THE BEGINNING OF COAGULATION. TJIPITIR, JAVA.

-A TREE OF PALAQUIUM TREUBII JUST TAPPED. THE MILK HAS A GREATER TEN-
DENCY TO RUN THAN IN PALAQUIUM GUTTA. TJIPITIR, JAVA.

29.— ABSENCE OF DEEP SCARS OR ANY TENDENCY TO DECAY OF A PALAQUIUM GUTTA
TREE, AFTER SEVERAL YEARS OF TAPPING. BUITENZORG, JAVA.

31

The principal gutta percha plantations now under cultivation
and in which much useful and desired experimenting is being done^
are located at Tjipitir and Buitenzorg in Java^ on Rhio Island
at Singapore and Bukit Timah on Singapore Island^ on Penang
Island, and at one or two places in the Federated Malay States.
Enough time and work have been spent to demonstrate most con-
clusively that gutta percha trees can be raised not only successfully
but also without much trouble or great outlay of money, and all
the nations having tropical possessions in the East, except the
United States, have made a start toward gutta percha plantations,
but the Dutch are the only ones so far who have gone into it on
a grand scale, and unless appearances are deceitful they will have
a monopoly on the plantations of the gutta percha of the future,
as sure as they have on the forest gutta percha of the present day.

X. SCIENTIFIC METHODS OF COLLECTING.

Modern methods of collecting gutta percha have advanced along
two lines. Needless to say they were not proposed nor carried out
by the wild native collectors who are unwilling to discontinue
])resent gains in favor of future returns. It was previously re-
marked that the gutta percha is all contained in the bark of the tree
and in the leaves. The problem resolved itself into either —

(a) Extracting some of the gutta percha from the bark and
leaves without injuring the tree, or ^'^

(h) Felling the tree and securing the gutta percha from all of
the bark and leaves.

To carry out the first proposition a method was devised similar
to that used in South America for extracting rubber milk, by which
incisions were made in the bark in a slanting direction up and down
the trunk (see fig. 27), so cut that the gutta percha ducts were
opened but no injury done to the inside wood of the tree. The milk
flowed out to a greater or less extent, and coagulated in strings on
the bark. After the flow had ceased and complete coagulation had
set in (one day) the strings of gutta percha were pulled off by hand,
washed in hot water, and pressed into cakes. The advantage of this
method was that no injury was done the tree although it was tapped
repeatedly. (See fig. 29.) The disadvantage lay in the fact that
only a small per cent of the total gutta percha in the tree could be
extracted at any one time. According to Van Romburgh^s (25)
latest experiments witli plantation trees (Palaquium gutta) about

32

15 to 17 years old^ the yield was 100 grams (nearly one-fifth of a
pound) per tree. The gutta percha thus secured was of the very
best.

In addition to the amount thus taken the leaves both from the
living and dead trees contain 8 to 10 per cent by weight of gutta
percha calculated to the dry leaf. To extract this gutta percha two
processes have been devised :

( 1 ) The mechanical one^ in which the leaf is ground to a powder
and then treated with hot water in such a way that the gutta percha
is gradually worked into a compact mass while the pulp of the leaf
is washed away. Up to the present the process has not been per-
fected^ for although the gutta percha contained is of a good quality
the percentage of recovery is smaller than it should be. The
largest factory of this kind is being erected near Singapore and it
proposes to use the leaves from a plantation of 100^000 trees on
the Island of Rhio^ some five hours from Singapore.

(2) The chemical process is carried out on the same lines as the
mechanical one so far as the grinding of the leaves is concerned.
The powder is then extracted with solvents and the dissolved gutta
percha recovered either through precipitation or through evapora-
tion of the solvent. The details of the process^ as well as the
solvents used^ are kept secret and no patents for this or the me-
chanical process have been taken out.

The largest factory producing gutta percha for the market is
located at Sarawak, North Borneo, and is very advantageously
situated as regards securing leaves from the surrounding gutta
percha forests. It has been claimed, however, that the factory de-
feated its avowed object of preventing the destruction of the trees,
for the native collectors employed would never risk their lives try-
ing to collect leaves from forest trees over 100 feet high when they
could gather them much easier by felling the tree and collecting a
goodly amount of gutta percha in addition. It thus appears that
the supply of leaves must come from a plantation where super-
vision can be exercised.

The plan of felling the gutta percha trees Of the forest and se-
curing all of the material from the bark and leaves is worthy of
serious consideration. In the first place the trees are surely doomed
as long as present conditions obtain. If the native can sell the
entire bark and leaves for more than he could get for the gutta
percha which he could extract, he will be tempted to bring then in.

3S

A second inducement for this method is the fact that many gutta
percha trees cut down even years previously have still much per-
fectly sound gutta percha in the rotting bark^ which could also be
secured. The process of recovering the substance from the bark is
practically the same as from the leaves^ and about the same per
cent is found there as well. With a yield of from ten to fifteen times
the present amount recovered from each tree the gutta percha
market would be relieved at once and the extermination of the
trees put oif many years, long enough at any rate to allow -planta-
tion trees to take their place.

A large amount of work has been done in this laboratory with the
purpose of finding a practical method for extracting the gutta
percha from the bark and leaves of the gutta percha trees. The
process calls for a solvent for the gutta percha which will dissolve
it easily, can be recovered and again used, and above all has no
deleterious effects on the substance.

The result of the experimentation led to a modification of the
Obach (26) hardening method for gutta percha. The process con-
sists in extracting the gutta percha bark and leaves by means of hot
gasoline, the apparatus being provided with reflux condensers.
When the gutta percha has entirely dissolved the solution is allowed
to stand until all of the dirt and most of the coloring matter has
settled. The clear supernatent liquid is then poured off and cooled
to 10° or 15"^ below freezing. The gutta, with a small amount of
resin, is thereby precipitated and can be filtered off through cloth
bags and dried. The resulting gutta can be further purified
by redissolving in distilled gasoline and reprecipitating. The fil-
trate containing the dissolved resins is redistilled and the recovered
gasoline used for effecting further solution of gutta percha, thus
making the process continuous.

The gutta so secured, on being warmed, can be pressed into any
desired form for experimentation. The gutta used in the above
experiments was so prepared, and the results of the physical and
chemical tests showed it to be unaffected by the process to any
appreciable extent. A year's exposure to laboratory fumes has not
changed the substance in any way. The accompanying figure (jSTo.
30) shows some of pressed cakes prepared in the laboratory.

It is to be noted that the process gives practically pure gutta and
not gutta percha, the resins remaining dissolved in the gasoline.
8766 3

34

This is in itself a great advantage, as the gntta could be used di-
rectly for bringing up the percentage in inferior grades of gutta
percha, and so make them suitable for cable insulation. The com-
mercial value of this gutta has not been determined, but should be
rated at about $600, Mexican, per picul, judging from the price
of the best gutta percha. In this way three piculs of Philippine
gutta percha at $210, Mexican, will produce 1 picul of pure gutta
valued at $600, Mexican, or a gain of $390 for every three piculs
of gutta percha (or the equivalent in bark and leaves) handled.

XI. PESTS AND PARASITES.

An instructive bulletin has been issued by Dr. Zimmerman (27)
of the ^s Lands Plantentuin at Buitenzorg, Java. His field of ob-
servation covered the large experimental gardens of Buitenzorg and
at Tjipitir, where many thousands of gutta percha trees of various
species are now growing. While the same conditions do not obtain
there as are encountered in the forest, it is certain that they are as
badly if not worse off on account of the multitude of insects of all
kinds which are attracted by the other plants of the gardens. In
fact he considers the test a severe one, and his conclusions that
there are practically no insect pests which might be considered dan-
gerous is very gratifying. Cattle and goats eat the leaves greedily
and young trees must therefore be protected until high enough to
be out of reach.

PART II. RUBBER.

I. HISTORICAL AND DESCRIPTIVE.

Even the shortest outline presenting the subject of rubber in its
historical^ geographical, botanical, and commercial aspects would be
beyond the scope of this report, nor does the part which the Philip-
pines have taken in its production or are likely to take for several
years to come, warrant an^^thing more than a brief explanation of
the present state of the rubber industry, in order to better under-
stand the present conditions here and the possibility of these islands
becoming a new center of the ever-increasing rubber industry.

Rubber, or India rubber, as it seems best known in the United
States, was discovered by the Spaniards in the second voyage of
Columbus. The Indians of Haiti were found playing with rubber
balls which they said were formed from the hardened milk of cer-
tain forest trees on the island. In 1755 Dom Jose, King of Portu-
gal, sent several pairs of his boots to South America to be coated
with rubber milk. They must have been made satisfactorily water-
proof, for the rubber industry has increased from that day to this.

Not alone was the valley of the Amazon found stocked with
rubber trees and vines, but new species were discovered in Central
America and Mexico as well. In 1798 rubber-producing vines and
trees were encountered in Southern Asia, later on in Central
Africa, and by the middle of the nineteenth century almost every
tropical country of the world had been searched, and the search had
not been in vain.

The number of genera and species — even the families represent-
ing the rubber plants — is very large, especially because the produc-
tion is not confined to trees alone nor to any one country, as is the
case with gutta percha, but includes a large number of vines as
well, and its area of production is practically that of the tropical
world. While rubber trees predominate in tropical America, Africa
and Asia apparently draw their greatest supply from vines. Borneo
especially is rich in them to the exclusion of trees. The Philippines

36

36

were said to contain more trees than vines^ but systematic search
has so far revealed only vines.

N^ot until the middle of the last century were the manifold uses
to which rubber could be applied well understood and the rubber
industry thoroughly established. Statistics show that London im-
ported in 1830 some 46^400 pounds of rubber^ and by 1870 this had
increased to the enormous amount of 15,211^800 pounds for that
one year alone. Since then the consumption has steadily increased,
the statistics reading by tons and not pounds, and for 1902
amounted to some 62,650 long tons. London, the former chief center
of the rubber trade, has retired in favor of New York. While tropical
America in the beginning produced nine-tenths of the rubber sup-
ply, it now exports but very little more than one-half of the total
amount, India, Burmah, Borneo, and Central Africa especially
having made giant strides in rubber production. Last yearns pro-
duction for the Malay States, Java, and Borneo was about 1,000
tons. In this was included the amount exported from the Philip-
pines. How much that amount was there is no way of finding out,
nor for how long this exportation of rubber has been going on.
My investigations in the southern islands convinced me that what-
ever collecting and exporting has been done concerns the island of
Tawi-Tawi alone, and in all probability the latter amount was small.
This conclusion is reached because the natives only of Tawi-Tawi
know of the commercial value of rubber, and also because I found
rubber vines very near the coast on Tawi-Tawi, a sure indication
that the search for rubber has not been very careful nor for a long
time.

The Philippine Islands are then practically a new field for the
development of a rubber industry. It will be my purpose, there-
fore, to show —

(1) The species of rubber-producing plants indigenous to the
islands and the amount of territory covered.

(2) The grade of rubber produced.

(3) The Philippines as a rubber-producing country: (a)
Through utilization of natural supply; (h) through introduction of
foreign species.

Eeference to figs. 31, 32, and 33 will show the two species of
vines now known to be well distributed over the islands, both of
which produce a good grade of rubber. Owing to my inability to

Fig. 31.— A RUBBER VINE (PARAMERIA PHILIPPINENSIS RADLK.) GROWING IN THE FOREST.

WESTERN MINDORO.

;■ y^;s /.{f -^v;:^t^; >^_?l;r^7cl^^^^ •■ '

• ' *' PlORA OF THE »»MtU»»WNE$.

"fyfyf'f <ftW>^.u.

'*,' |l?^, i«* <«*«.««* »i^^,,?»«\:

Fig. 32— rubber VINE (PARAMERIA PHILIPPINENSIS RADLK.) GROWING IN GREAT ABUNDANCE
ON THE ISLANDS OF MINDORO AND CULION.

Fig. 33 —rubber VINE FOUND IN TAWI-TAWI, BASILAN, AND MINDANAO. SPECIES
UNDETERMINED.

Fig. 34.— rubber VINE (WILLUGHBEIA FIRMA BLUME). THIS SPECIES SUPPLIES MOST OF THE
RUBBER PRODUCED IN BORNEO. BOTANICAL GARDEN, SINGAPORE, STRAITS SETTLEMENTS.

37

find a vine in fruit or flower, one of them has not yet been deter-
mined botanically. Mr Merrill contributes the following botanical
descriptions :

Parameria philippmensis Radlk. ( Apocinaceae ) .

An evergreen woody vine, reaching a height of 40 or 50 feet and a
diameter of 1 inch or more. Bark gray, with an abundant milky sap.
Leaves opposite, ovate, acute or somewhat acuminate, glabrous, 2 to 3
inches long; nerves four pairs; petioles short. Flowers small, white,
fragrant, in terminal panicles. Fruit a long, slender, distinctly torulose
follicle, 10 to 12 inches long, the swellings over the seeds an inch apart.
Seeds one-half inch long, brown, coma white, about twice as long as the
seed.

{Apocinaceoe.) Genus undetermined, specimen with leaves only, from the
Island of Basilan.

A very large vine 150 to 200 feet in length, with a diameter of 6 to 8
inches, the bark somewhat rough, greenish. Leaves broadly ovate or
orbicular, 8 to 10 inches long, abruptly very shortly acuminate, the acu-
men less than one-half inch long, glabrous above, pubescent on the nerves
beneath, the nerves prominent, about 10 pairs.

It has already been stated that no rubber-producing trees have
been found. That is to say a great many species of trees have been
discovered which are known to produce a milk or latex, and while
none so far studied contain rubber, it is scarcely to be supposed
that when material from all has been collected some at least will
not be found to yield a good product. ^

The extent of territory covered by these two Sirober vines is given
by map No. 2 (facing page 9). While the Parameria is found in
Mindoro, Culion, and the other northern islands, the indetermined
species is found on Tawi-Tawi, Basilan, and Mindanao. The extent
of territory covered in these various places was estimated after ex-
tensive personal investigations when all available data had been
secured from natives, merchants, etc. In the northern islands, ex-
cepting Mindoro, the area covered is given as reported by those who
found specimens of the vine. There is every reason to believe, how-
ever, that careful investigations would show much larger areas. In
Mindoro the natives in all the coast towns knew the rubber vine as
"Dactang Ahas^^ (medicine for snakes), and many of them brought
us samples from the neighboring forest. They all reported large
numbers of vines in the interior of the island, and the three expedi-
tions made there from the north, west, and south sides confirmed
their statements.

88

In Mindanao the two areas given between Dinas and Tueuran
in the mountains near the south coast are the only ones known so
far, and even these were only found by accident. The natives knew
nothing of rubber, but they had a vine which contained a milky
substance, good either as a medicine or for making the heads of
their drum sticks. On securing a piece of this peculiar substance
from the latter it was found to be a good sample of rubber. Fur-
ther explorations to the west and east will probably prove that this
vine covers about the same area as that occupied by the gutta percha
trees.

In Basilan and Tawi-Tawi the vine grows abundantly and to a
large size. In the latter island the Moros understand its commer-
cial value, and those engaged in collecting gutta percha gather
rubber at the same time, sometimes mixing the rubber and gutta
milk.

II. THE GRADE OF RUBBER PRODUCED.

Eubber milk or latex is contained in the bark of certain vines
and trees in exactly the same manner as is gutta percha. (See
fig. 35.) When made to flow, the same phenomenon of coagulation
apparently sets in quickly or slowly, according to the species of the
plant. In many species of trees the coagulation is very slow and
the flow of milk more abundant than with gutta percha trees. As
a result the natives have evolved the method of tapping the trees
similar to that shown in fig. 36. The milk thus secured is coagu-
lated in a manner similar to that employed with gutta percha.

Another method, which seems to give the best results and which
is employed in the preparation of Para rubber, consists in subject-
ing thin layers of the milk, placed on the broad end of a paddle,
to the coagulating action of smoke produced by burning certain
husks which are similar to those of cocoanuts. The smoke contains
creosote and acid fumes, which quickly destroy all fungus growths
and bacteria which might tend to cause decomposition of the rub-
ber, while the heat removes the greater part of the moisture at the
same time.

A chemical analysis of many grades of rubber coming from dif-
ferent species of trees. and vines shows them, with the exception of
Variable amounts of water and dirt, to be composed almost entirely
of rubber, with a small per cent of resins. The rubber in all has
apparently the same chemical composition, an ultimate analysis

Fig. 36.— method OF TAPPING A PARA RUBBER TREE, THIRD DAY AFTER TAPPING.
EXPERIMENTAL GARDEN, BUITENZORG, JAVA.

39

giving the formula CioHie- Chemically then, there appears to be
only one rubber, while physically certain differences are to be found
between samples from different species. Whether the superiority
of Para rubber is due, therefore, to the excellency of the rubber
itself or to the above-mentioned method of coagulation has not yet
been determined. However, it is a fact that Para rubber from the
tree species Hevea brasiliensis Muell. Arg., is recognized as the
standard for grading rubber commercially.

It will be noted that the method before mentioned is one requir-
ing skill, judgment, and the expenditure of considerable labor. In
most rubber countries the native collectors possess none of these
requisites and are content to employ the crudest methods. In
consequence, the rubber obtained is of a low grade even though
the species of tree is of the best.

The Philippine rubber collectors are Samal and Joloano Moros
living in Tawi-Tawi and the adjacent coral islands. The method
of coagulation used by them was undoubtedly learned from the
Moros of North Borneo, who with the Dyaks collect much of the
rubber in that island. It consists in first pulling the vine down
to the ground so as to be better able to tap it along its entire length.
The milk is caught in cocoanut shells or leaves, and coagulated by
pouring into sea water. The coagulation k> almost instantaneous,
and when properly manipulated a large amount of water can be
mechanically inclosed inside the large balls along with plenty of
chopped-up bark. The resulting rubber, of which I secured many
samples, is white, tough, and very elastic so long as it is kept in
sea water. On exposure to the air it blackens and decomposition
slowly sets in.

The chemical analysis of a sample of this rubber, after much
of the dirt and water had been removed, resulted as follows :

Per cent.

Dirt 3.76

Rubber 81.57

Resins 3.16

Water 11.51

Judging from this analysis the rubber in Singapore would bo
rated as Borneo No. 1, which sells for $125, Mexican, per picul of
133^ pounds.

The vines generally die after being pulled down and tapped,

40

probably because of their inability to again reach light and sunshine.
The rubber from the Mindoro species has never apparently been
gathered in any quantities even by the natives. When the bark
is cut the milk flows readily and coagulates quickly. In appearance
it is very similar to the Tawi-Tawi rubber. As yet no chemical
analysis has been made. In order to get a valuation of it, a sample
was submitted to the Goodyear Eubber Company, of Akron, Ohio,
who placed it at about 60 cents per pound after allowance is made
for the percentage of water. Larger samples of both kinds of rub-
ber are now being prepared in the laboratory in order that they may
be submitted simultaneously to rubber experts.

III. THE PHILIPPINES AS A RUBBER-PRODUCING COUNTRY.

(a) THROUGH UTILIZATION OF THE NATURAL SUPPLY.

Judging from the way the natives of Tawi-Tawi gathered rubber
when left to their own devices, I was convinced that they wasted
as large amounts of the milk as they did when they collected gutta
percha, that is, ten to forty times more than they took away. It
is evident then that under present conditions the history of the
rubber vines will be the same as that of the gutta percha trees, only
on a smaller scale. It is useless, in my opinion, to think of tapping
them only, for an inspection of their tortuous windings up and
around the high forest trees (see fig. 37) will show the impossi-
bility of ever collecting the milk, no matter how carefully the tap-
ping were done.

To get the full value from the vine the rubber must be extracted
from the entire bark. Experiments along that line are now in
progress in the laboratory and so far promise well. If the entire
vine be cut into pieces and dried, the bark easily separates from the
wood, and forms 44 per cent of the entire plant. By grinding the
bark in any ordinary mill, the rubber separates in the form of small
balls while the bark passes off as powder. The dried bark contains
9 to 10 per cent by weight of pure rubber, which shows this sub-
stance to be about 4 per cent of the entire vine. The other condi-
tions and details will be investigated by the laboratory with a view
of determining methods which will make possible the investment
of American capital.

It is true that the method of collecting rubber given above kills
the vine. The answer to this objection is found in the fact that

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BOTANICAL GARDEN, SINGAPORE, STRAITS SETTLEMENTS.

41

when the vine has been cut off, the roots stool again quickly. On
a hillside in Mindoro where the natives had burned the forest for
the purpose of planting rice, scores of stools from rubber vines were
counted while the fire was yet smouldering in some of the old
stumps and roots of the large trees.

(h) THROUGH INTKODUCTION OF FOREIGN SPECIES.

It was stated previously that no rubber trees were found in the
Islands. Exception should be made to the beautiful specimens of
the India Eubber tree {Ficus elastica Linn.) which were introduced
throughout the Archipelago by the Spanish years ago as ornamen-
tal shade trees rather than as rubber producers. They are excellent
examples of the way foreign species of rubber trees will grow here,
and may also serve the still better purpose, that of furnishing seeds
and slips to start rubber plantations. Many plantations of this
tree have been begun in Java, the reasons for the selection of this
species being: (1) The seeds are numerous and the plants grow
well; (2) the method of starting new plants by marcottage (see
fig. 25) succeeds admirably and the plants have vigorous growth
(see fig. 38) ; (3) the method of coagulation best suited for this
milk is the simplest of all. It consists of making many small cuts
in the bark of the trunk, and allowing the flowing milk to coagulate
in strings. When dry and hard they are pulled off and pressed
into a compact mass (see mass of rubber on the left, fig. 39) for
shipment. The work can be done by even ignorant workmen and
with no damage to the tree.

In the Malay States a great many plantations are now being
started with Para rubber trees, the seeds of which are secured from
the various governinent botanical gardens as well as from private
plantations. (See fig. 41.) One of this species of trees is now
growing in Manila, and apparently the climate is suitable. The
Bureau of Agriculture has distributed many Ceara rubber seeds
during the past year, and the growth of the seedlings is marvelous.

In general the climatic conditions of most of the islands seem
very favorable for the rubber industry. Mindoro and the southern
islands especially are advantageous on account of the abundant
rainfall distributed throughout the year, with no long season of
drought.

What p'ests and parasites the rubber trees would be troubled with
can only be conjectured by reference to the experiences of Java, etc.

42

Dr. Zimmerman (28) extended his work on parasites to include
rubber trees, and has found one or two species of insects that may
cause damage. Cattle and goats must also be guarded against.

It is needless to dwell on the commercial side of rubber planta-
tions. They are now flourishing in all tropical countries and as an
agricultural investment are highly considered. However, in all
new countries, a certain amount of experimental work must be done
before large capital can be safely invested. In India, Burmah, the
Malay States, and Java this has been accomplished by the respective
governments. As soon as methods were perfected and seed supplies
provided, private capital began operations at once. From the num-
ber of inquiries already made about rubber planting in these Is-
lands, it would look as if some movements in this direction are
contemplated here, investors only waiting for the Government to
pave the way. By profiting from the extensive experience of our
neighboring countries the experimental era should be short and
inexpensive, as a great deal of the pioneer work has been done.

LITERATURE.

( 1 ) "Die Gutta Percha," by Dr. Eugene Obach. P. 6.

(2) Mech. Magazine. London, 1846. Vol. 45, p. 415.

(3) C. W. Siemens, Journal of Soc. of Telegraphic Engineers, 1876.
Vol. 5, p. 82.

(4) London Jour. Botany, 1847. Vol. 6, p. 463.

(5) Flora de Filipinas, 1837. P. 40.

(6) "Die Gutta Percha," Obach. P. 59.

(7) "Die Gutta Percha," Obach. P. 15.

( 8 ) Personal communication.

(9) Jour. Straits Branch, Asiat. Soc, 1884. No. 12, pp. 212-214.

(10) "Die Gutta Percha," Obach. P. 24.

(11) E. Jungfleisch, "La Production de la Gutta Percha." Paris, 1892,
p. 4.

(12) Vid. Export Statistics from Bureau of Forestry, 1901, 1902, 1903.

(13) Rules and Regulations of the Bureau of Forestry fpr Utilization
of Forest Products, 1900.

(14) Bulletin de Tlnstitut Botanique de Buitenzorg, No. XV, p. 28.

(15) Rep. Chem. appliqu6; vol. 1, p. 455. Jahresber. d. Chemie, 1859,
p. 517.

(16) "Die Gutta Percha," Obach. P. 27.

(17) Bulletin de L'Institut Botanique de Buitenzorg, No. XV, p. 22.

(18) "Die Gutta Percha," Obach. P. 8.

43

(19) On Isoprene and Caoutchine, C. G. Williams, Proc. Roy. Soc, 1860.
Vol. 10, p. 516. Harris, Ber. d. chem. Ges. 35, 3256, and Weber, Ber. d.
chem. Ges. 33, 779.

(20) Chem. News, 1882. Vol. 46, p. 120, and 1892, vol. 65, p. 265.
Comptes Rendus, 1875, vol. 80, p. 1446; 1879, vol. 89, pp. 361 and 1117.

(21) Jour. Prakt. Chem., 1897. Vol. 55, pp. 1 and 4. Jour. Russ. Phys.-
Chem. Soc, 1896 [1] 316.

(22) "Die Gutta Percha," Obach. Pp. 28, 30, 34, etc.

(23) "Die Gutta Percha," Obach. P. 87.

(24) "Caoutchouc en Getah-Pertja." Mededeelingen uit 's Lands Plan-
tentuin. No. XXXIX.

(25) Private communication.

(26) "Die Gutta Percha," Obach. P. 49.

( 27 ) Bulletin de L'Institut Botanique de Buitenzorg, No. X.

(28) Bulletin de L'Institut Botanique de Buitenzorg, No. X.

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