18, 5 Valencia: Commercial Philippine Timbers 499 
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Fic. 9. Apparatus used in making shearing tests. 
MOISTURE CONTENT 
Tiemann ® says: 
Water exists in green wood in two forms: As liquid water contained 
in the cavities of the cells or pores, and as “imbibed” or hygroscopic water 
intimately absorbed in the substance of which the wood is composed. The 
removal of the free water from the holes or pores will evidently have no 
effect upon the physical properties or shrinkage of the wood, but as soon 
88 any of the “imbibed” moisture is removed from the cell walls shrinkage 
begins to take place and other changes occur. The strength also begins to 
increase at this time. The point where the cell walls, or wood substance, 
become saturated is called the “fiber saturation point,” * * : * The 
fiber saturation point lies between moisture condition of 25 and 30 per 
cent, of the dry weight of the wood, depending on the species. * * * 
Air-dried wood will rarely dry below 12 to 14 per cent. 
Moisture content is the weight of water contained in the wood, 
€xpressed in per cent of the oven-dry weight of the wood. It is 
determined by Weighing a small section of the test specimen 
and then drying it at 100°C. in an electric furnace until its 
Weight becomes constant; the loss of weight is then divided by 
* Journ. Franklin Inst. 188 (1919) 27-50. 
