TANNINS 93 



tannin, 3.8. It gave a satisfactory leather of reddish tan with 

 firm texture and good grain, but the process of tanning was slow. 

 Gana believed that owing to the good quality of the leather 

 produced and the availability of pine trees, the utilization of 

 this bark as a tanning material was commercially important. 



Family CUNONIACEAE 



Genus WEINMANNIA 

 WEINMANNIA LU20NIENSIS Vidal. 



It has been found by the St. Louis College at Baguio that 

 this species furnishes good tanbark. 



Weinmannia luzoniensis is a tree reaching a height of 20 me- 

 ters and a diameter of 50 centimeters. The leaves are opposite, 

 and compound with three to seven leaflets, which are leathery, 

 pointed at both ends, 4 to 10 centimeters in length, and with 

 toothed margins. The flowers are fairly small, white or pinkish, 

 and borne on racemes. 



This species is found in the mountains of Luzon and is ap- 

 parently fairly common in some localities. 



Family LEGUMINOSAE 



Genus PITHECOLOBIUM 

 PITHECOLOBIUM DULCE (Roxb.) Benth. Kamachile. 



A description and figure and the local names of this species 

 are given in the section on food plants. 



Gana,* who has made a study of Philippine tanneries, writes 

 as follows concerning this species : 



Camanchile bark is used almost exclusively by Filipino tanners, who 

 prefer it on account of the light-colored leather it produces. Because 

 of this demand the price of air-dried camanchile bark has risen as high 

 as 10 pesos per 100 kilograms. The tree is widely scattered throughout 

 the Islands, although nowhere systematically or extensively grown. The 

 present annual consumption of bark amounts to about 1,500 tons. Ex- 

 haustion of the supply is threatened, as the trees are commonly killed 

 by too extensive stripping of the bark. The bark is brownish gray and 

 rough outside and reddish brown inside. It produces dull but light-colored 

 leather, which reddens on exposure to light. An infusion of it contains 

 a tannin of the catechol class, which gives a green-black precipitate with 

 iron salts, a light brown precipitate with bromine water, and crimson 

 line when in contact with one drop of concentrated sulphuric acid. Upon 

 analysis a representative sample of the bark gave the following results, 



* Gana, V. Q., The leather industry of the Philippine Islands. Philippine 

 Journal of Science, Section A, Volume 10 (1915). page 353. 



