264 The Philippine Journal of Science 1916 



Like the bark of the majority of the Coniferse ^ the bark of 

 the Philippine pine (Pinus insularis) is low in tannin content." 

 However, the good quality of the leather produced and the avail- 

 ability of pine trees make it commercially important. The area 

 of the pine forest is estimated at 518,000 hectares,^^ or 5 per 

 cent of the public forest of the Philippines. The collection of 

 bark should be easy, as the tree is used for lumber and at pre- 

 sent the bark is waste. Whitford states that there is little 

 doubt that, if fires were kept oif, the pine (in the absence of 

 broad-leaved competition) would quickly seed the entire area, 

 for its reproduction is very rapid. 



Pinus insularis has been investigated, but no work has been 

 done on Pinus merkusii, which occurs in Mindoro ^^ in pure 

 stands and in open groves scattered throughout the grasslands, 

 southwest of a high mountain mass. The samples used in this 

 work were collected in the vicinity of Baguio, Benguet, by the 

 Bureau of Forestry. They were 60 centimeters wide and 1.5 

 centimeters thick. The outside surface was dark gray, grooved, 

 and scaly. This epidermal layer resembled cork; it contained 

 no tanning principles. The inner surface was brownish and 

 somewhat fibrous or woody. 



Narra. — The bark of the narra tree has a fairly high tannin 

 content and produces good leather. However, the timber is so 

 widely scattered that it is doubtful if it will ever be available 

 for tanning. 



Pili. — The bark of this tree is suitable for tanning purposes 

 and produces a satisfactory yellowish brown leather. However, 

 it is not likely that this bark will be available on a commercial 

 scale, because the tree produces valuable nuts and high-priced 

 resin.^' It is not abundant, nor is it systematically grown, and 

 its propagation should be encouraged. The sample of bark col- 

 lected in Ambos Camarines by the Bureau of Forestry was 2 



'Procter's Principles of Leather Manufacture (1903), 246. 



^'' Barks containing 3 to 15 per cent of catehol tannins are used in Styria, 

 Austria, and in Russia. Pinus cembra, which grows in the Alps and which 

 contains 3 to 5 per cent tannin, is used in Tyrol. The pin sauvage of France 

 contains from 4 to 5 per cent. Hemlock bark, obtained from the hemlock 

 fir which is abundant in the northern and western parts of the United States 

 and in Canada, forms the staple tanning material of the United States [H. 

 G. Bennett, Manufacture of Leather (1914), 186]. It contains from 8 to 

 11 per cent of tannin with much phlobaphenes. 



"Whitford, H. N., Bull. P. I. Bur. Forestry (1911), No. 10, 17. 



" Ibid., 31. 



"Clover, A. M., This Journal, Sec. A (1907), 2, 1-40. 



