ECONOMIC POSSIBILITIES OF MANGROVE SWAMPS. 



49 



structural uses in wet places. Analyses show 4 to 6 per cent tannin. 

 The leaves assav about the same. 



Table I. — Analyses of hark of Rhizophora mucronata Lam.' 



Sample No. 



Diam- 

 eter of 

 tree. 



Parts per 100 of water-free 



material. 1 



1 



iDSOl- 



uble. 



Total 

 extract. 



Non- 

 tannfn. 



Tan- 

 nin. 



1 ... 



Cm. 

 23 



60.4 

 60.8 

 68.5 

 75.7 

 67.6 

 65.0 

 99.1 

 58.6 

 58.0 

 54.3 

 56.2 

 60.0 

 61.2 

 56.0 

 63.9 

 57.0 

 55.2 

 56.4 

 56.4 

 55.1 

 61.8 

 61.0 



39.6 

 39.2 

 31.5 

 24.3 

 32.4 

 35.0 

 40.9 

 41.4 

 42.0 

 45.7 

 43.8 

 40.0 

 38.8 

 43.4 

 36.1 

 43.0 

 44.8 

 43.6 

 43.6 

 44.9 

 38.2 

 39.0 

 41.5 



15.7 

 13.7 

 15.7 

 12.0 

 11.1 

 14.6 

 14.7 

 12.5 

 11.4 

 11.9 

 14.9 

 13.0 

 12.4 

 12.9 

 15.3 

 12.7 

 15.0 

 11.2 

 11. « 

 15.8 

 11.8 

 12.7 

 13.3 



23.9 

 25.5 

 15.8 

 12.3 

 21.3 

 20.4 

 26.2 

 28.9 

 30.6 

 33.8 

 28.9 

 27.0 

 26.4 

 30 5 

 20.8 

 30.3 

 29.8 

 32.4 

 31.8 

 29.1 

 26.4 

 26.3 

 28.2 



9 . 



23 

 13 

 15 

 20 

 30 

 32 

 25 

 22 

 23 

 25 

 30 

 30 

 45 

 20 



20 

 to 

 25 



10'' . _ 



11" 



18 



28 



45.. . 



60..... .. 



63 



64 _ 



65 . 



66- 



69. 



72 :_ 



73 ._ 



80 



81. ... . 



82 



83 



84 



85 



86 



87 



Average 



1 ""* " 





59.2 



40.8 



13.2 



27.6 



j 



» An average tree will yield bark to the value of 4.97 pesos, at 0.286 peso per kilogram. 

 One ton of fresh bark is worth 35.50 pesos. The peso Philippine currency is equal to 

 fifty cents United States currency ; 0.286 peso per kilogram equals 0.065 dollar, per pound. 



These figures do not represent the value of the bark as such, but of the total tannin 

 present at the current price of tannin extracts. (Letter of A. Klipstein & Co., New York, 

 July 22, 1910). They are given for the purpose of comparing the various barks. 



I" Excluded from average as undersized tree. 



A composite of the above samples gave 2,8 per cent "difficulty soluble" 

 tannins or "reds." 



Rhizophora conjugata Linn. Bacaua>' (Tagalog). 



This tree in every way is similar to the preceding, but is much less 

 common, amounting perhaps to one-tenth of the bark-producing timber. 

 The bark is somewhat lighter in color when fresh than that of Rhizophora 

 mucronata, while the woods of the two species are practicably indistin- 

 guishable. 



101334 4 



