OUR COMMON WOODS 



223 



woods. If the rays are quite conspicuous and the wood 

 is hard and heavy, it is oak, as the key given later will show. 

 Close attention to the details of the key will enal^le one to 

 decide to what group of oaks it belongs. 



In most cases the structure will not stand out so promi- 

 nently as in oak, so that it is necessary to make a careful 

 study with the hand lens. If pores appear, their arrange- 

 ment, both in the early wood and in the late wood, should 

 be carefully noted; also whether the pores are open or 

 filled with a froth-like substance known as tyloses. Wood 



White Ash 



Black Ash 



Fig. 148. — (Magnified about 8 times.) 



parenchyma lines should l)e looked for, and if present, the 

 arrangement of the lines should be noted. 



If no pores appear under the magnifying lens, look 

 closely for resin ducts. If these are found, note whether 

 they are large or small, numerous or scattered, open or 

 closed, lighter or darker than the wood. Note also whether 

 the late wood is very heavy and hard, showing a decided 

 contrast to the early wood, or fairly soft and grading into 

 the early wood without abrupt change. Weigh the piece 

 in your hand, smell a fresh-cut surface to detect the odor, 

 if any, and taste a chip to see if anything characteristic 

 is discoverable. Then turn to the following key: 



