SP PHILIPPINE RESINS, GUMS, AND OILS 
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surface, and the resulting resin is generally mixed with chips 
of bark. 
When the resin first exudes from the tree, it appears as almost 
colorless tears, the outer surfaces of which soon harden. As 
exudation continues, the fresh resin instead of flowing out over 
the first portion produced appears to force the latter outward by 
being deposited beneath it. The outer surfaces are thus always 
hard and friable and the inner portion hardens very slowly. 
About two weeks are required to produce solid pieces of market- 
able size. 
The Manila copal which is exported from the Philippines 
directly to the United States is cleaned, sorted, and graded in 
Manila. Particular attention is paid to cleanliness, color, and 
size. Manila copal is sometimes adulterated with other resins, 
particularly dipterocarp resins; the latter, however, are very 
readily distinguished from Manila copal. As the resin is col- 
lected largely by non-Christian tribes, the sorters in Manila 
frequently encounter considerable admixtures of other resins, 
and as the consumers have to depend largely on Philippine 
sorters, it is not surprising that the securing of a uniform quality 
of resin is a matter of some difficulty. 
ANALYSIS OF MANILA COPAL 
Almaciga has been the subject of a number of investigations 
by the Bureau of Science.* 
Richmond examined recent surface and fossil (mineral) resin 
to ascertain the probable composition and character of these 
substances. The acid value was determined by dissolving ap- 
proximately one gram of powdered resin in 50 cubic centimeters 
of absolute alcohol and titrating with a half-normal solution 
of alcoholic potassium hydroxide, using phenolphthalein as an 
indicator. A gram of surface resin required approximately 
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128 milligrams of potash for neutralization, while a gram of — 
“mineral resin required about 110. 
The saponification value was determined in the following 
manner :—About one gram of resin was dissolved in 50 cubic 
centimeters of absolute alcohol. Twenty-five cubic centimeters 

* Foxworthy, F. W., The almaciga tree: Agathis alba (Lam.), Philippine 
Journal of Science, Section A, Volume 5 (1910), pages 173 to 175. 
Richmond, G. F., Manila copal. Philippine Journal of Science, Section 
A, Volume 5 (1910), pages 177 to 201. 
Brooks, B. T., The destructive distillation of Manila copal. Philippine 
Journal of Science, Section A, Volume 5 (1910), pages 203 to 217. 
Brooks, B. T., The oxidation of Manila copal by the air. Philippine 
Journal of Science, Section A, Volume 5 (1910), pages 219 to 227. 
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