RESINS 29 



posed to light and air. At intervals of 78 days, 13 months, and 

 2 years, the copal was weighed and the acid and iodine values 

 determined. His results showed that the acid value was prac- 

 tically unchanged while the iodine value decreased. He also 

 determined the solubility of Manila copal in various solvents, 

 and suggested a method for estimating Manila copal in the 

 presence of other resins. He believed that Manila copal, which 

 is cheaper than kauri resin, could be used in place of the latter 

 in certain dental-mould preparations. 



DESCRIPTION AND DISTRIBUTION OF AGATHIS ALBA 



Agathis alba is a large tree reaching a height of 50 to 60 

 meters and a diameter, at breast height, of niore than 2 meters ; 

 and with a clear length of trunk of 30 meters or more. The 

 bark is 10 to 15 millimeters in thickness, brittle, and light 

 greenish to brownish gray in color. It is shed in scroll-shaped 

 patterns and is thickly set with corky pustules. The inner 

 bark is brown, streaked with red and grading into a cream color 

 near the sapwood. The leaves are simple, opposite or nearly so, 

 leathery in texture, 3 to 9.5 centimeters long, and 1 to 2.5 centi- 

 meters wide. 



The wood is moderately hard, flexible, and tough, though not 

 resilient. The heartwood is pale yellow, sometimes with a faint 

 pinkish or brownish tinge, generally turning to an even, very 

 pale brown in drying. 



This species was first described at length by Rumphius, who 

 called it Dammara alba, which is the Latin form of the Malay 

 common name, dammar puti. The same name was used by 

 Lamarck in 1786, but the genus has since come to be known 

 as Agathis, a name which is retained in the Vienna Code. 



Agathis alba is found growing in considerable numbers in 

 forests at altitudes of from 200 to 2,000 meters, but in the Phil- 

 ippines it usually attains its best development on well-drained 

 slopes at from 600 to 1,500 meters elevation. The tree is very 

 common in the Philippines and exists on mountain slopes 

 throughout the Archipelago. It has been reported from the 

 following regions: Cagayan, Isabela, Lepanto, Benguet, Abra, 

 Zambales, Nueva Ecija, Bataan, Rizal, Tayabas, Polillo, Min- 

 doro, Camarines, Albay, Sorsogon, Calayan Island, Sibuyan, 

 Negros, Samar, Palawan, Misamis, Davao, and Zamboanga. 

 Agathis alba also occurs in Cochin China, the Malay Peninsula, 

 Sumatra, Java, Celebes, the Moluccas, and Borneo. 



