20 PHILIPPINE RESINS, GUMS, AND OILS 
True copals are hard, lustrous, yellow, brown, or nearly white, and 
more or less insoluble in the usual solvents, but are rendered soluble by 
melting before making into varnish. 
The copals are resins which contain those very permanent 
substances known as resenes. 
Bottler and Sabin * state that: 
* *  * they contain, moreover, ethereal oils, which are driven off by 
melting or distillation, a bitter principle, and coloring-matter. Zanzibar 
and Cameroon copals consist mainly of resin acids and resenes; * * * 
Manila is composed mostly of resin acids; but it contains more resene (12 
per cent) than does Zanzibar (6 per cent). * * * 
Bottler and Sabin + further say: 
For making spirit copal varnishes only such copals can be used as will 
readily dissolve to a clear solution, free from slimy or stringy qualities. 
Manila and Borneo copals are used, the soft Angola and the newer Sierra 
Leone. : 
These varnishes may be made by such formulas as the following: 
Parts. 
(qd). Mamlaveopal®:.. = ve Ch Ses eee es ae eee 16 
‘Venice, turpentine A=). eae ee ee eee 4to5 
Alcohols (95eper cent) i 2. sites ieee ty oe 30 
The resin of Agathis alba is found in the bark, and oozes out 
whenever the latter is cut (surface resin). Occasionally lumps 
of resin are found in the forks of branches, and large masses, 
the so-called fossil (mineral) resins, are found in the ground. 
These deposits are located by sounding the ground with sharp- 
pointed sticks. Such resin is often discovered in places where 
large trees have formerly stood, but which have long since died 
and decayed, leaving large masses of resin in the ground. 
According to Richmond,t more than 50 per cent of the Manila 
copal exported from the Philippines is collected in the Davao 
district of Mindanao, and probably 90 per cent of the resin pro- 
duced in that region is obtained by blazing living trees. The 
best results are secured by removing, from different sides of 
trees, strips of bark about one meter in length and 20 to 30 
centimeters wide, thus providing clean surfaces on which the 
resin is deposited as it oozes from the cut end of the bark. The 
resin is also obtained by means of a wedge-shaped incision in 
the tree trunk. This method however does not provide a clean 

* Bottler, M. and Sabin, A. H., German and American varnish making 
(1912), page 138. 
+ Bottler, M. and Sabin, A. H., German and American varnish making 
(1912), page 131. 
~ Richmond, G. F., Manila copal. Philippine Journal of Science, Section 
A, Volume 5 (1910), pages 177 to 201. 
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