46 WILLIAMS. 



value of 250,409 dollars, found their way to American ports in 1909. 

 The swamps of the Malayan region also have been a considerable source 

 of supply. These barks, although of the same species as the East Afri- 

 can, contain only 25 to 30 per cent of tannin as compared with 35 to 40 

 per cent in the latter. For this reason, exports have been limited to the 

 manufactured extract known as cutch. A number of companies have 

 successfully been operating in Borneo, Java, and Sumatra for several 

 years. American tanners bought 700 tons of this extract in 1909, 

 at a cost of 43,566 dollars. The article entered the United States 

 duty free until March 1906 (Treasury Decision No. 27197) when it 

 was declared dutiable. This caused a general decrease in production 

 and closed one Borneo factory. Under the Payne tariff of 1909 cutch 

 is dutiable at seven-eighths of a cent per pound. 



The advantage which the Philippines enjoys in this respect promises 

 to give opportunity for a profitable cutch industry in the Archipelago. 

 All the species of mangroves of any importance in the Eastern tropics are 

 found in the Philippines. The area of the swamps, though small com- 

 pared with those of Borneo, Sumatra, and the Malay Peninsula, is con- 

 siderable. The Bureau of Forestry estimates the total virgin swamps 

 of the Philippines at 207,200 hectares, which includes an area of 25,000 

 hectares of well-developed swamps in Sibuguey Bay, Mindanao, a 10,000- 

 hectare tract in Mindoro, and a fairly compact area of good swamp in 

 Palawan; but on other islands than the three mentioned the swamps are 

 so scattered as to render profitable cutch manufacture very doubtful. 

 The swamps of Tayabas and the Sulu Archipelago should perhaps be 

 excepted. 



"In ^ Mindoro, Palawan, and Mindanao, the Rhizophoracew reach as large size 

 as anywhere in their range. Sonneratia also seems to reach its maximum de- 

 velopment in Mindanao." 



Only a few carefully estimated figures are to be found upon the tannin con- 

 tent of mangrove barks. Analyses made near the source of supply have not 

 to any extent been published. Apparently, samples analyzed elsewhere fre- 

 quently have lost much of their tannin before reaching the chemist. Busse ' 

 reports analyses of some East African barks and gives for comparison those 

 of barks from the same region made by the "Deutche Grerberschule zu Freiburg." 



Bruguiera gymhorrhiza Lam. 

 Ceriops candolleana Am. 

 Xylocarpus granatum or X. obovatus 

 Rhizophora mucronata Lam. 



" Foxworthy, F. W. Distribution and Utilization of the Mangrove Swamps • 

 of Malaya. Ann. Jard. Bot., Supplement III, Buitenzorg (1909), II, 319. 

 'Ari. a. d. kais Gsndhtsmt. (1899), 15, 177-184. 



Tannin 

 Berlin (Busse 



(per cent). 



;). Freiburg. 



51.64 



24.60 



42.27 



27.50 



40.49 



8.70 



47.99 



21.30 



