Patinas on prehistoric and antique bronze artifacts deposited in the National Museum in Prague, Czechoslovakia, were studied using x-ray diffraction analysis and infrared absorption spectroscopy. It was confirmed from the character, structure, and composition of the patina studied that these surface corrosion products had been formed during their soil deposition. The active bronze corrosion caused by air pollution, e.g., sulfur dioxide and NO_x, was not proved because of favorable climatic and microclimatic conditions for materials such as bronze artifacts in the National Museum and in ancient metal artifact depositories.