Frost And Snow. Occasionally in Lapland the phenomenon of the formation of snow is witnessed when the door of an apartment in which persons are assembled is suddenly opened and a blast of cold air admitted, the watery vapour exhaled by their respiration being instantly frozen into flukes. Snow is a bad conductor of heat, or cold, and therefore acts as a most valuable covering for vegetables and seeds; wheat continues to grow beneath its covering, though every blade would be cut off if exposed to the frosty air. Let us not forget how beautiful and varied are the forms of its flakes, when looked at through a magnifying glass, or microscope. (See Heat and Cold, p. 42).