Desiccation Chamber – A container designed to dry objects, such as rained-on books. It is possible to make a simple desiccation chamber with readily available materials.

Dormant – The non-growing phase of an organism. In the case of molds, a mold body can become dormant if the environment is no longer hospitable to growth. Some species of mold form a protective casing around the fungal body during such times. When the climate becomes supportive of mold growth, the protective casing opens, and the fungus resumes growing.

Extrinsic Allergic Alveolitis – An infammatory immune response in the lungs, often triggered by prolonged exposure to irritants such as mold particles, spores, paper particles or dust.

“Farmer’s Lung” – An occupational illness associated with some kinds of farming. See “Librarian’s Lung.”

Foxing – Marks that form on paper as a result of acids in the paper reacting to moisture in the air. This is not mold; rather, it is a chemical reaction. Usually, foxing is a golden yellow, but can also be tan or brown depending upon the paper’s content and the environment the book has been in.

Fungus (pl. Fungi) – A kingdom of organisms separate from plants and animals. Unlike plants, fungi do not have chlorophyll. Instead, most fungi get their energy from digesting decaying plants and animals. Mold is a kind of fungus.

HVAC system – Heating Ventilation and Air Conditioning system. The best kinds have built-in filtration that removes particles as small as spores from treated air.

Hygrometer – A tool used to measure Relative Humidity. The kind of measuring device described in this web site is specifically known as a psychrometer.

Hypersensitivity Pneumonitis – An inflammatory immune response. See Extrinsic Allergic Alveolitis.

Hypha (pl. Hyphae) – Long thin hairlike strands that form the body of mold.

Kingdom – In biology, kingdom refers to a grouping of different living organisms. Kingdom is the first level of sorting different organisms by type. Organisms in the fungus kingdom include mushrooms, molds and yeasts.

“Librarian’s Lung” – Considered an occupational illness for librarians. There is some debate whether this condition is connected to inhaling paper dust or mold spores; however, the majority of web sites I have queried make a connection between increased respiratory sensitivity to allergens and prolonged exposure to mold spores.

“Mystery Muck” – Unidentifiable dirt found on or inside of a book. “Mystery muck” often looks suspiciously like its original source was food or something sticky.

Mycology – The study of fungi.

Relative Humidity – The amount of water that is present in the air as a gas. The warmer the temperature, the larger the amount of water that is able to exist in the air as a gas.

Signature – A section of folded paper within a book, often stitched into the binding

Spores – Part of the reproductive process of molds. Spores are similar to seeds that plants produce because they contain the genetic material needed to produce new mold growth. Unlike plant seeds, spores do not contain as much food storage to spur initial growth. Spores are resistant to environments that would be inhospitable to mold and can remain dormant for many years.