80 PHILIPPINE RESINS, GUMS, AND OILS 
water to which petroleum has been added. The petroleum is ‘ 
said to facilitate the removal of dirt and resin. After the 
first boiling the gutta-percha is ground and boiled again with 
water, the process being repeated several times. This method 
apparently results in a high-grade product. 
Gutta-percha is now being grown successfully in plantations 
in a number of tropical countries, but not in the Philippines. 
According to Foxworthy: * 
Successful extraction of gutta from the leaves is done by the Dutch 
and the cultural methods Boos in the plantation are devoted exclusively 
to leaf production. 2 
No great development of the gutta-percha industry in the 
Philippine Islands can be expected until the trees are grown 
in plantations. 
The most important use of gutta-percha is for the insulation 
of submarine and underground electrical cables. It is also 
utilized considerably in the manufacture of surgical appliances, 
funnels, bottles, and other articles which come in frequent con- 
tact with acids. For these purposes it is valuable on account 
of the ease with which it can be sterilized and its resistance to 
acids. A familiar form is as the outer covering of golf balls. 
Palaquium ahernianum is a tree reaching a height of about 
40 meters and a diameter of 1.5 meters. The leaves are alter- 
nate, pointed at both ends, wider toward the tip than near the 
base, from 12 to 20 centimeters long, the lower surface velvety 
and with a rusty color. The flowers occur singly or in groups 
of two or three on wart-like growths on the stem. The fruits 
are one-seeded, somewhat rounded, and about 2.5 centimeters 
in diameter. 
This species is apparently confined to Mindanao, 
Genus PAYENA 
PAYENA LEERIi Kurz. (Fig. 29). 
GUTTA-PERCHA 
According to Heyne7y this tree produces a very good grade 
of gutta-percha. 
This species has been collected once in Mindanao and once 
in Tawi-Tawi. 

* Foxworthy, F. W., Minor forest products and jungle produce. ‘Gov- 
ernment of British North Borneo, Department of Forestry Bulletin No. 1, 
Part II (1916), page 45. 
+ Heyne, K., De Nuttige Planten van Nederlandsch-Indié, Volume. 4 
(1917), page 12. 
€ 
c 
