water and carbon dioxide.
The Nature of Wood Wood consists of three
primary materials: cellulose and
hemicellulose, which form the framework and
the filler of all plant cell walls, and lignin, a
reinforcing material that binds neighboring
cell walls together and gives wood its
strength. Cellulose and hemicellulose are both
aggregates of sugar molecules (pp. 265,266).
Lignin is made of intricately inter-locked
phenolic molecules — essentially rings of
carbon atoms with various additional
chemical groups attached — and is one of the
most complex natural substances known. The
higher the lignin content of a wood, the harder
it is and the hotter it burns; its combustion
releases 50% more heat than cellulose.
Mesquite wood is well-known for its high-
temperature fire, which it owes to its 64%
lignin content (hickory, a common hardwood,
is 18% lignin). Most wood also contains a