262 



The Philippine Journal of Science 



1916 



tanning industry, the Bureau of Science has undertaken this 

 investigation of the barks of some of the common trees of the 

 Philippine Islands that may have tanning properties. The re- 

 sults obtained with the following barks have already been 

 published.^ 



Common name. 



Cateban and ulayan. 



Balinghasay. 



Pagsahinging. 



Calamansanay. 



Ligas. 



Sacat fruits. 



Botanical name. ^ 



Querciis sp. 



Buchanania arborescens. 

 Canarium villosum. 

 Nauclea calysina. 

 Semicarpus accuminatissima. 

 Terminalia nitens. 



The present work deals with the barks of the following trees : 



Common name. Botanical name. 



Pine. Pinus insularis. 



Narra. Pterocarpus vidalianus. 



Palo maria. Calophyllum inophyllum. 



Alibangbang. Bauhinia malabarica. 



Pili. Canarium luzonicum. 



Oak. Quercus sp. 



Acacia, raintree. Enterolobium saman. 



Bulak, kapok. Ceiba pentandra. 



Tuba. Jatropha curcas. 



Bignay. Sporosa sp. 



Of the above list, the acacia, or raintree; kapok, or cotton 

 tree; tuba; and bignay contain little or no tannin. 



Although some of the others are low in tannin, their great 

 abundance renders them of value to the tanner, especially in 

 localities where there is no other tanning material. The chemical 

 analyses of the barks are given in Table I. 



Table I. — Chemical analyses of some Philippine barks. 



[Numbers give percentages.] 







Calculated to dry basis. 





Tree. 



Moisture. 







Color of the 

 infusions. 



Total ex- 

 tracts. 



Tannins. 



Nontan- 

 nins. 



Pine, Finns insularis 



15.5 



6.6 



3.8 



2.8 



Wine red. 



Narra, Pterocarpus vidalianus 



15.1 



41.9 



30.7 



11.2 



Deep wine red. 



Palo maria, Calophyllum inophyl- 

 lum. 



10.2 



16.9 



11.9 



5.0 



Wine red. 



Alibangbang-, Bauhinia malaba- 

 rica. 



12.4 



22.8 



9.5 



13.3 



Do. 



Pili, Canarium luzonicum ,_ 



11.3 



11.2 



7.8 



3.4 



Wine red with 

 yellow tinge. 



Oak, Quercus sp 



10.5 



22.4 



17.9 



4.5 



Deep wine red. 



This .Journal, Sec. A (1915), 10, 349. 



