The Structure of Ordinary Water: New data and interpretations are yielding new insights into this fascinating substance.

The train of thought pursued in this article has led to the conclusion that the structure of cold water seems likely to consist, for the most part, of hydrogen-bonded, four-coordinated, framework regions, with interstitial monomers occupying some fraction of the cavities the framework encloses. The precise geometry of the framework has not been specified, but some evidence suggests that it is rather regular at low temperatures and becomes more random as the water gets warmer. These conclusions, meager as they are in comparison with what we shall eventually need to know about water, are still "subject to change without notice." Such a change would, for instance, be made necessary by the discrediting either of the data or of the interpretations on which the model is based. The discovery of new facts, or of new meanings in old facts, which were clearly in conflict with the model, would also make it necessary to modify, if not to abandon, it. Even this would be progress, however, for it would be another product of the method of drawing upon data from diverse sources and would be a further step toward the progressively more comprehensive model to which this method will lead and the progressively greater confidence we will be able to place in our conclusions.