This journal article describes the effects of the physical, chemical and biological environment on the deterioration (degradation) and preservation of various museum, archival and library materials, particularly paper and leather. Topics include pollution (dust, particulate matter, contaminants, acidic gases, oxidants, sulphur dioxide or SO2, oxides of nitrogen and ozone, photochemical smog), atmospheric or ambient and relative humidity (RH), radiant energy (sunlight, photochemical radiation, heat or temperature), microbiological agents (eg. mold, mildew, fungi), insect infestations, light (levels, visible, ultraviolet radiation or UV), environmental controls (eg. air-conditioning, heating, ventilation, air filtration, humidification). Other topics mentioned but not discussed include human damage (handling, accidents, vandalism), and disasters (flood, fire). An extensive list of references date from 1928-1969. This article is a general reference for conservation and museum climatology.