** 
362 FOXTVOItTTTV. 
CHEMICAL PROPERTIES. 
It is not the intention here to treat of the oheniieal composition of 
wood or of its behavior under any but the simplest reagents. However, 
there are a few very simple tests which may aid in the determination of 
particuLir woods and these are included here: 
ilolave {Vitex spp.) turns to a bright greonish-yellow when treated with an 
alkaline solution; narra {Pterocarpus spp.) gives a fluorescent, blue color to 
water; betis {Ulipe hetis (Blco.) Merr.) or bansalaguin (Mimusops elengi L.) 
will form a lather if the surface of the MOod be rubbed with water or saliva; 
ealunipit {TerminaUa edutis Blco.), dalinsi (T. pellucida Presl.) sacat (T. nitens 
Presl.), or taiisay (T. cafappa L.) will color water a dirty, straw-yellow; catmon 
{Dillenia spp.) causes water to become pale red. 
Others of our woods will doubtless also be found to give distinct re- 
actions with simple reagents.^ 
3. DURABILITY AND DECAY. 
Fungi and haderia. — These grow abundantly in warm and moist 
situations. Wood which is partly submerged, or in contact with the 
ground, is most subject to the attack of these organisms, a continual 
supply of moisture favoring their development. Piling, railroad ties, 
and portions of buildings in contact with the ground give the bCvSt 
illustrations of destruction by these means, but while wood is always 
liable to damage from these causes, they are not the most serious con- 
siderations in this climate. 
Beetles. — Woods frequently are encoiTnterod which are completely 
riddled by the burrows of wood-boring beetles ; these extend in all direc- 
tions and very perceptibly weaken the wood. The presence of beetles is 
indicatcfl by the open burrows or by fine wood dust pushed out from 
them. It is said that no woods are entirely immune from beetle attack. 
In the very hard woods, however, it is usually only the sapwood which 
is affected. Logs left in the forest or piled witli beetle-eaten material 
are most subject to attack. Certain woods, such as dita. {Alstonia 
sclioJaris R. Br.) and lanete {Wrlghtia spp.), are particularly liable to 
be damaged in this way. Xo entirely satisfactory means of preventing 
beetle attacks has as yet been found. 
Anay or "white ants/' — Termites, very generally known in the Islands 
as ami.y, destroy a great many of the softer woods, completely hollowing 
them out until only a shell is left. 
Sliipwrn-m or teredo. — This is the most serious enemy to piling, boat 
^^ r 
keels, and other wooden articles which are immersed in sea water. The 
work of these small animals constitutes so serious a nuisance as to render 
any but a very few of our very hard woods useless for piling. 
*A discussion of the mechanical properties of wood is given in Timber, Bull. 10, 
U. S. Bur. For., and for a discussion of the mechanical properties of Philippine 
woods the reader is referred to Gardner, Bull. For. Bur., Manila (190G), 4, 
(1907), 2d edition. 
