1394. Snow is formed by the freezing of the vapours in the atmosphere. It differs from hail and hoar frost, in being, as it were, crystallised, while they are not. As the flakes fall down through the atmosphere, they are continually joined by more of these radiated spicula, and they increase in bulk like the drops of rain or hailstones. The lightness of snow, although it is firm ice, is owing to the excess of its surface in comparison with the matter contained under it: as gold itself may be extended in surface till it will ride upon the least breath of air. The whiteness of snow is owing to the small particles into which it is divided; for ice, when pounded, will become equally white.