It may here be worth while to mention that it is not invariably true that a substance gets contracted, and the molecules more and more pressed together, as it assumes a solid form. There is at least one exception. If we take 1,700 pints of steam, the water, as I said, on becoming cool enough to lose the vapourous form, will shrink into a measure holding a single pint; if we cooled lower still, it will get smaller and smaller in bulk (though of course not at all at the same rate) till it arrives at a point when it is just going to freeze; then suddenly (7 degrees above the freezing point) it again begins to expand. Ice occupies more space than cold water; its molecules get arranged in a particular manner by their crystallization. On the admission of an _intelligent_ Creator providing, by beneficent design, the laws of matter, it is easy to give a reason for this useful property. It prevents the inhabitants of northern climates being deprived of a supply of water. As it is, the solid water or ice expands, and, becoming lighter, forms at the top of the water, and the heavier warmer water remains below. But if ice always got denser and sank, the warmer liquid would be perpetually displaced and so come up to the surface, where it would freeze and sink in its turn. In a short time, then, all our water supplies would (whenever the temperature went down to freezing, which it constantly does in winter) be turned into solid ice. This would be a source of the gravest inconvenience to the population of a cold climate. If we deny a designing mind, the alternative is that this property of water is a mere chance.