Until the fundamental work of Morey and Bowen, it was not known what the compositions and properties of the compounds which are formed by the devitrification of common soda-lime glasses were, and there had been no attempt made to determine the equilibrium relations between crystalline and liquid phases. This paper relates to the entire system: Na2O.SiO2-CaO.SiO2-SiO2, with special attention not given to the region of direct interest in glass technology. An extended discussion is given of the devitrification of glass, in which it is shown that the liquidus temperature is the only datum point which is solely a function of glass composition, and is unaffected by the past history of the glass or by fortuitous circumstances at the time devitrification is taking place.
