The Nature of Snow

Abstract

ALL ice and snow forms are crystalline. To demonstrate the crystalline structure of even an apparently non-crystalline body such as a shapeless block of ice, Tyndall passed a beam of light through it. If we repeat this experiment we find that hexagonal cavities are produced and that the process of crystallization is, as it were, reversed, so that we get what are sometimes called ‘negative crystals', or as I prefer to call them, ‘negative figures', within the body of the ice (Fig. 1). As the action of the beam proceeds, each figure becomes filled with the water which occupied it as ice. In the centre of each figure a bubble forms, which, in reality, is a vacuous sphere due to the water taking up less space than the ice.