THE ECONOMIC POSSIBILITIES OF THE MANGROVE 

 SWAMPS OF THE PHILIPPINES. 



By Eayiiond F. Bacon and Vicente Q. Gana. 

 (From the Chemical Laboratory, Bureau of Scieiice, Manila, P. I. 



In the United States, and in other countries . wliere large amounts 

 of leather are manufactured, the forests yielding native tanning materials 

 have been so far exliausted that these nations must look to other 

 countries for their source of supply. At the present time very large 

 quantities of tan barks and cutch are imported into the United States from 

 Borneo, Dutch East Africa, Brazil and other tropical countries, and the 

 use of mangrove tanning materials is constantly increasing. The most 

 abundant source ot tanning substances in the Philippines is the mangrove 

 swamps of the Islands. At the present time there is no mangrove bark 

 exported from the Philippines, and as yet the area of these swamps is not 

 known. They occur as narrow fringes along the coast or in considerable 

 areas at the mouths of large rivers, especially at the head of bays. Some 

 limited areas have been mapped and measured by the Forestry Bureau. 

 These are as follows: 



(1) Island of Mindoro, about 10,000 hectares, which will yield approximately 

 50,000 tons of bark. 



(2) The east coast of the Zamboanga Peninsula, Mindanao, contains about 

 9,000 hectares of mangrove swamp ; this will yield at least 90,000 tons of bark, 

 found on a coast line about 45 miles in length. In the same region, on the 

 other side of the Gulf of Subuguay, there are probably 9,000 hectares more which 

 will also yield at least 10 tons per hectare. With the exception of a number of 

 areas of 1,000 hectares or less, no further regions have been examined carefully. 

 The above statement gives a very small proportion of the total area of the 

 mangrove swamps. It is believed that the swamps of Mindanao alone will yield 

 enough bark to furnish a continuous supply to a very large cutch factory. 



The tan barks of Mindanao average from 33 to 25 per cent of tannin, 

 and these are the best that have thus far Ijeen examined from the Islands. 

 Such bark could not be profitably shipped to the United States to 

 compete with the East African barks carrying 50 per cent of tannin. 

 A careful analysis of conditions shows that the only method of handling 

 the tan barks commercially is by means of a cutch factory at the source 

 of supply and it appears that such a factory could be operated very 

 profitably, as soon as there is free trade between the Philippines and 



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