The authors discuss a number of chemical tests and procedures which are used in conservation. Among the processes examined are: the use of barium salts on stone for protection from sulfuric acid which results from air pollution, corrosion of metals and the use of electrolytic cleaning, PbCO₃ encrusted lead, the use of benzotriazole for green spots caused by copper chlorides, and the treatment of fibrous artifacts to protect them from air-borne acids. Also briefly covered are some techniques of chemical testing used in museums. These techniques include: spot tests, emission spectroscopy, neutron activation analysis, various x-ray techniques, laser, and gas chromatography. These tests can be used both for analysis and authentication. -- AATA