If the surface of a glass can be treated as an impure silica surface, then certain conclusions can be drawn regarding its molecular properties. Its chemistry will be related to its thermal history. Heat treatment will affect both the degree and nature of the phase separation that occurs in the glasses. This in turn affects the degree of leaching of the glass surface regardless of gross phase separation. Immersion of glass surfaces in aqueous solutions results in Nadeficient surfaces and gives rise to surfaces enriched in both silica and potential Lewis acid sites. Further heat treatment of the surface controls the ratio of single to hydrogen-bonded hydroxyl groups, and this affects the adsorption properties of the silica portion of the surface. -- AATA