The occurrence of various efflorescences on objects stored in wooden museum cases is described. These are calclacite (calcium acetate chloride penthydrate) and a related compound; lead formate (on lead objects); and other formate and acetate efflorescences, all of which depend on the presence of organic acid vapors. Sodium nitrate, calcium nitrate and sodium chloride also occur. See also 8-1620. E.W.F. -- AATA