This entry consists of several articles dealing with studies and experiments relating to preservation and conservation of works of art, which were subjected to experiments with acids and alkaloids to simulate natural and artificial atmospheric conditions, which result in deterioration and degradation of the surfaces of the art objects. Studies were done on damage to art by micro-organisms, including some showing complete infiltration by mold, and identification and subsequent destruction of the microflora implicated. Where the art was stained and discolored, restoration was done through the use of salt solutions to chlorinate the affected areas. The article by Maria Froehlich concerns the preservation of tempura paints on wood, and the effect of damage by microflora to these art objects made of pine and other hard woods. The other articles describe other studies of techniques for drying wood that has been recovered in recent archeological discoveries, while wet or moist. Natural lacquers and varnishes seldom function adequately in preserving an oil painting, since it may be seriously affected by crystallization as a result of moisture.