The Dew-drop is familiar to every one from earliest infancy. Resting in luminous beads on the down of leaves, or pendent from the finest blades of grass, or threaded upon the floating lines of the gossamer, its “orient pearl” varies in size from the diameter of a small pea to the most minute atom that can be imagined to exist. Each of these, like the rain-drops, has the properties of reflecting and refracting light; hence, from so many minute prisms, the unfolded rays of the sun are sent up to the eye in colours of brilliancy similar to those of the rainbow. When the sunbeams traverse horizontally a very thickly-bedewed grass-plot, these colours arrange themselves so as to form an iris, or dew-bow; and if we select any one of these drops for observation, and steadily regard it while we gradually change our position, we shall find the prismatic colours follow each other in their regular order.--_Wells._ FALL OF DEW IN ONE YEAR. The annual average quantity of Dew deposited in this country is estimated at a depth of about five inches, being about one-seventh of the mean quantity of moisture supposed to be received from the atmosphere all over Great Britain in the year; or about 22,161,337,355 tons, taking the ton at 252 imperial gallons.--_Wells._ GRADUATED SUPPLY OF DEW TO VEGETATION. Each of the different grasses draws from the atmosphere during the night a supply of dew to recruit its energies dependent upon its form and peculiar radiating power. Every flower has a power of radiation of its own, subject to changes during the day and night, and the deposition of moisture on it is regulated by the peculiar law which this radiating power obeys; and this power will be influenced by the aspect which the flower presents to the sky, unfolding to the contemplative mind the most beautiful example of creative wisdom.[39] WARMTH OF SNOW IN ARCTIC LATITUDES.