A brief review of the chemistry of glass making through the ages with references to recent studies on alkali sources, component/trace minerals, weathering layers, decolorization, maiolica, lead glasses, colored frit, and sealing-wax red. Types of glass from various archaeo-logical sites and the results of their analyses are given. The conclusion discusses three major points: the formation of color and opacity, lead in glass, and glass trade. -- AATA