Corrosion theory is discussed. The most common corrosion type is electrochemical oxidation. Describes the following types of corrosion: galvanic, pit, intergranular, tension, cyclic due to mechanical loading, abrasive, and slit. Environmental conditions are discussed, with sections on the effects of air pollutants on metals, indoor versus outdoor climates, and corrosion by organic acids. Suggests reading of the British Defense Ministry standard (1977) for prevention of corrosion of metals from organic materials and recommends a climate with a relative humidity below 60-70% at worst, removal of all dust and soot, and use of carbon filters.