V4 MANGROVE SWAMPS 
it would appear that the moisture content is fairly constant for 
the different species. Cox found that in the Philipines, where 
the humidity is high and fairly constant, the variations in the 
moisture content are much less than where the climate is hot 
or cold, moist or dry, according to the season. He concluded that 
the moisture content of wood seldom falls below 12.5 or 13 per 
cent of the dry weight, and that these figures may be taken 
as good averages for thoroughly seasoned firewoods. The ash 
content varies considerably in different species. Cox says of 
the ash content that this is of comparatively little importance 
from the standpoint of firewood because the amount of ash is 
usually small. The calorific value based on the dry weight of 
the various species is fairly constant, as might be expected 
from the fact that the part of the wood left after deducting 
the water and ash would be almost the same in all cases. 
TABLE XXI.—Specific gravities of Philippine firewoods. 
[The numbers and common names are those given by Cox in the original table. The 
scientific names have been inserted by Mr. E. E. Schneider, wood expert of the Bureau 
of Forestry, after a recent examination of specimens of the wood used by Cox.] 















= : : Se ee Wey pe ae — 
| | | = 
No. Common name. Scientific name. Moisture.| Ash. | See 
Ardea OES. amt z ime ai | 
| Per cent. | Per cent. 
; : || 18.58 1.46 | 0.7671 
Sulmeototan =]. 22 5. esses o ee Bruguiera conjugata____--------- | 13.51 144 | -ocmdat 
| b12. 10 2.29 | ¢0. 9861 
4 Batauan:sa>: Sees se ee Rhizophora mucronata_____------ a1. 46 p98 \eQvgaed 
eee 181 -\-2 5 eee 
5 | Bacao -_-------.-----------| BY LORILEN CISD ae tee eee 174 
| ; | 4 { 12.26 5.75 | 0.8799 
6) | Bacauan=tubis2===- S22 IBTROUUCTIU BD eae ae | 11.88 5.57 |. 0.8732 
| . . | . 
f 13.24 1.29 0.9136 
fe aC atinta nme eee eee See oe DSLR NOT RKCIORS eee es ees = | 13,08 1.981 30: BRE 
| | 5 : K 
| 13. 71 2.80 | 0.7412 
%)| Labieues_-_- Sick SARE Soe 2 Xylocarpus moluccensis____------ 12.98 0. 7age 
| | D1) eee Ses I 
: 13. 07 2.12 0. 996 
OF Bacauanwss= 32> sae BTU OU TeNnGiS eee ee ee | 42.97 9. 06 | 0/ast 
613.00 2.72 | 0.5954 
10) Lambu-tamb tw eoe2—- = = Xylocarpus moluccensis ____---=-- | 412.50 | 2.711 0.5668 
| : ; 12. 94 2.65 | 0.6688 
| (SU arabia theese oes Sonneratia caseolaris -------- --- ; o-xotas’t 9. 62 | Ov6Sa7 
| | a. . . 
| | | 12.78 } 2.41:} ¢1. 071 
|) Sas aca a ee ees Rhizophora candelaria _____------ i 12.4 o\og:| “antag 
| 3 3 , 
13.25 | 1.60 | 0.890 
15 Vangal, ei Pee 3 (Geniopsitaoal eee ste = en ane aa ‘L 13:09 Gee 
| lf 18.24 1.55 | 0.9426 
16  Pototan ___- beeen aea=a==-| Sruguiera Cong g dtd 12. 68 0, 9836 
| | "63°22 eae b 
late 37 1.65 | 0.8936 
Pir Mens eadh a =2- 2 ee ae Bruguiera parviflora_____---_--_- } 13.32 0. 3881 
USseacdipa ts ass= ss. meee Sonneratia caseolaris___---------- (a) |2 2 0.8186 
19-| Pagatpatee ese ees Sonneratia caseolaris -___--------- | (f) tet 0. 8447 
a Air-dry. 4 Sapwood. 
b Heartwood beginning to form. e Heavier than water. 
¢ The heartwood sinks. tf Unseasoned. 
