ABSTRACT
Metals are particularly liable to attack and can corrode very quickly. For example, organic acids can act as a catalyst for the reaction between lead and carbon dioxide. The reaction causes the surface of lead to be covered by a white powdery layer of lead carbonate. If the reaction is allowed to continue, loss of surface detail and ultimately disintegration will follow. While this type of damage is easy to see, other types of decay such as the effect of formaldehyde on leather, which makes it brittle, are not always so obvious.
