OF THE STRUCTURE OF WOOD AND HERBS. 



87 



beheld in the section of the English Oak, are arranged along the inner margin of 

 each annual ring of wood; the distance between the two clusters being the thick- 

 ness of one years growth of wood. The wood itself appears like lace- work, being 

 filled with minute pores, varying in diameter from one twelve hundred and 

 fiftieth part of an inch to one twenty-five hundredth. 



Fig. 131. 



