Wood
Description
The hard, fibrous tissue composing the trunk, branches, and roots of trees and shrubs. Wood is a renewable resource that is abundantly available and versatile in its usefulness. It has been used for tools, structures, and as an art material since earliest times. Wood is primarily composed of cellulose (40-60% ), hemicelluloses (15-25%), lignin (15-40%). It can also contain resins, dyes, tannins, waxes, and oils. Wood is still used throughout the world for lumber, furniture, paper, pulp, and fuel. Over 3000 species of trees produce wood. They are categorized as either hardwood (angiosperm) or softwood (gymnosperm) trees. Identification and characterization of wood are based on the following properties (Gettens and Stout 1966):
- Annual leaf, flower and fruit formation and release (deciduous or evergreen)
- Color of heartwood (interior mature wood) and sapwood (outer actively growing wood).
- Visibility and size of growth rings
- Cell size and variation for spring wood (formed at the beginning of the growing season) and summerwood (formed at the end of the growing season).
- Size and number of medullary rays
- Pore size and distribution.
Examples of hardwoods include: Ash, Basswood, Beech, Birch, Cherry, Chestnut, Elm, Fruitwood, Gum, hackberry, Hazel, Hickory, Holly, Lacewood, Linden, locust, Magnolia, Mahogany, Maple, Mulberry, Oak, Olive, Poplar, Rosewood, Satinwood, Sycamore, Tupelo, Walnut, Willow.
Examples of softwoods include: Cedar, Cypress, Fir, Larch, Pine, Redwood, Spruce
Synonyms and Related Terms =
lumber; bois (Fr.); madera (Esp.); madeira (Port.); legno (It.)
Risks
Wood is deteriorated by primarily by insect and microbiological infestations.
Physical and Chemical Properties
Insoluble in water and organic solvents, but will swell and absorb most liquids.
Resources and Citations
- Alden Identification Services, Microscopic Wood Identification: Link
- Encyclopedia Britannica, http://www.britannica.com Comment: "wood" [Accessed November 7, 2001].
- R. Bruce Hoadley, Identifying Wood, The Taunton Press, Newton, CT, 1990
- R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966
- G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 874
- Hermann Kuhn, Conservation and Restoration of Works of Art and Antiquities, Butterworths, London, 1986
- Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982
- Pam Hatchfield, Pollutants in the Museum Environment, Archetype Press, London, 2002