GLOSSARY

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H

hardwood

Wood obtained from a class of tree known as Angiosperms, such as birch, oak, eucalyptus, maple and poplar. These trees are characterised by broad leaves and are usually deciduous in temperate zones. While most of these trees have strong, hard woods, the term does not refer to a wood's strength; some hardwoods, like balsa, are actually quite soft.

hazard assessment

Assessment of potential internal and external risks to the collection. See also Disaster preparedness.

heartwood

The hard, central wood in the trunk of a tree, containing comparatively little moisture and no sap. See also Sapwood.

herbicide

Any chemical substance used to destroy plants, especially weeds. See Pesticide.

Heritage Collections Council (HCC)

Established in 1996 by the Cultural Ministers Council. The HCC is responsible for the publication of this package, the coordination of a National Conservation strategy for preventative conservation, and the development of the Australian Museums On Line (AMOL).

hinge

A flexible paper strip-often made from Japanese paper-used to attach an artwork to its mat along one edge, allowing it to be lifted for inspection of its verso.

Material, usually gummed cloth tape, which joins the window board to the backboard of a mat along one edge, thereby permitting the window board to be opened. See also Mounts, mats.

humectant

A substance which attracts, absorbs or retains moisture, for example, glycerol and sorbitol. Humectants can be used to rehumidify some objects, like leather, to help restore their flexibility.

humidification

The gradual introduction of moisture, often through the use of mechanical devices, for example, humidifiers.

hydrogen bonding

A strong chemical bond formed when two electronegative atoms are joined through a hydrogen atom, either in the same or another molecule.

The strongest hydrogen bonds are found in compounds containing fluorine, oxygen or nitrogen.

hydrolysis

A chemical action involving water. In the case of organic compounds, it involves decomposition by interaction with water.

hygroscope

A material with the ability to attract and hold water molecules. Extremely hygroscopic materials take up a large percentage of their weight in water in conditions of high humidity.