TANBARKS 12] 
TABLE XXVIII.—Yield of bark from mangrove trees of different sizes. 
[Data from Foxworthy and Matthews. ] 






Species. 
Bru- | Ceri 
gies) |emhi- |) Riis) | Meonse: ) exealiceaal 
* | zophora | zophora | gata and, Ceriops 
| eande- | mucro- Bru- | rox- 
laria. nata. guiera burgh- 
sexan- lana, 
gula. 
\ Inches. | Kilos. | Kilos. | Kilos. | Kilos. | 
~~ 3 4 4 3 2 | 
4 | 6 | 6 | 5 3 | 
5 | 12 | 11 | 7 5 
6 | 21 19 | 9 | 9 | 
7 | 30 30 16 13 
8 | 41 41 18 21 
9 | 56 52 24 30 
10 72 66 | 30 40 
11 90 83 | 39 54 
12 110 98 | CG eae a 
13 133 121 Fi () (Reka 
14 157 145 | 663] $= sees 
15 193 | 178 | (3) |e -- ose 
16 236 223 Otalte ek 
17 287 266 | LORE eee | 
ape eee ces | Pale es. | 120i ee 
1p ee ee a 130) |Meeeee 






In Table XXVIII is shown the yield of bark from trees of 
‘different sizes of Rhizophora candelaria, Rhizophora mucronata, 
Bruguiera conjugata and Bruguiera sexangula, and Certops 
tagal and Ceriops roxburghiana. The figures in this table were 
calculated from a table by Foxworthy and Matthews.* 
Very various results have been obtained by analyzing the 
barks of the same species, and it has been often stated that the 
bark from some countries is richer in tannin than that from 
others. Williams} says that the percentage of tannin in- 
creases with the size of the tree. He believed, however, that 
this increase was due rather to the age than to the size. In 
drying, barks also lose a certain portion of their tannin, es- 
pecially if not properly dried. Owing to these facts and to the 
varied results obtained by analyses it is questionable as to 

* Foxworthy, F. W. and Matthews, D. M., Mangrove and nipah swamps 
of British North Borneo, Department of Forestry Bulletin No. 3 (1917), 
page 16. 
+ Williams, R. R., The economic possibilities of the mangrove swamps 
of the Philippines, Philippine Journal of Science, Sec. A, Vol. 6 (1911), 
pages 45 to 61. 
