24 TIMBER.' 



COLOR AND ODOR. 



Color, like structure, lends beauty to the wood, aids in its identifica- 

 tion, and is of great value in the determination of its quality. Con- 

 sidering only the heartwood, the black color of the persimmon, the 

 dark brown of the walnut, the light brown of the white oaks, the red- 

 dish brown of the red oaks, the yellowish white of the tulip and poplar, 

 the brownish red of the redwood and cedar, the yellow of the papaw 

 and sumac, are all reliable marks of distinction; and color together 

 with luster and weight are only too often the only features depended 

 upon in practice. Newly formed wood, like that of the outer few rings, 

 has but little color. The sapwood generally is light, and the wood of 

 trees which form no heartwood changes but little, except when stained 

 by forerunners of disease. 



The different tints of colors, whether the brown of oak, the orange 

 brown of pine, the blackish tint of walnut, or the reddish cast of cedar, 

 are due to pigments, while the deeper shade of the summer-wood bands 

 in pine and cedar, or in oak or walnut, is due to the fact that the wood 

 being denser, more of the colored wood substance occurs on a given 

 space, i. e., there is more colored matter per square inch. 



Wood is translucent, a thin disk of pine permitting light to pass 

 through quite freely. This translucency affects the luster and bright- 

 ness of lumber. When wood is attacked by fungi it becomes more 

 opaque, loses its brightness, and in practice is designated " dead " in 

 distinction to "live" or bright timber. Exposure to air darkens all 

 wood; direct sunlight and occasional moistening hasten this change 

 and cause it to penetrate deeper. Prolonged immersion has the same 

 effect, pine wood becoming a dark gray while oak changes to a blackish 

 brown. 



Odor, like color, depends on chemical compounds, forming no part of 

 the wood substance itself. Exposure to weather reduces, and often 

 changes the odor, but a piece of dry longleaf pine, cedar, or camphor 

 wood exhales apparently as much odor as ever, when a new surface is 

 exposed. 



Heartwood is more odoriferous than sapwood. Many kinds of wood 

 are distinguished by strong and peculiar odors. This is especially the 

 case with camphor, cedar, pine, oak, and mahogany, and the list would 

 comprise every kind of wood in use, were our sense of smell developed 

 in keeping with its importance. Decomposition is usually accompanied 

 by pronounced odors; decaying poplar emits a disagreeable odor, 

 while red oak often becomes fragrant, its smell resembling that of 

 heliotrope. 



RESONANCE. 



If a log or scantling is struck with the ax or hammer, a sound is 

 emitted which varies in pitch and character with the shape and size of 

 the stick, and also with the kind and condition of wood. Not only can 



