5. _Spiculæ, or prisms having one or both extremities inserted in the centre of a lamellar crystal._ This genus resembles a pair of wheels, united by an axle-tree. In low temperatures, the greatest proportion of crystals that fall are, probably, perfect geometrical figures. Some of the general varieties in the figures of the crystals may be referred to the temperature of the air; but the particular and endless modifications of similar classes of crystals can only be referred to the pleasure of the great First Cause, whose works, even the most minute and evanescent, and in regions the most remote from human observation, bear the impress of His own hand, and display to his intelligent creatures his vast and beneficent wisdom. If, on these forms of unintelligent matter, he has bestowed such excellent workmanship, with how much more transcendent loveliness will he clothe those who are redeemed by the exceeding riches of his grace, and who, beyond the history and productions of all worlds, will reflect the beauty of his glorious countenance! _Frost-rime_, or frost-smoke, is a meteor peculiar to those parts of the globe where a very low temperature prevails for a considerable time. It consists of a dense frozen vapour, apparently arising out of the sea, or any large sheet of water, and ascending, in high winds and turbulent seas, to the height of eighty or one hundred feet, but, in light breezes and smooth water, creeping along the surface. The particles of which it consists are as small as dust, and cleave to the rigging of ships, or almost any substance against which they are driven by the wind, and afford a coating of an inch or upwards in depth. These particles adhere to one another until the windward surface of the ropes is covered, and form long fibres somewhat of a prismatical or pyramidal shape, having their points directed towards the wind. Frost-rime adheres readily to articles of clothing; and, from the circumstance of its lodging in the hair, and giving it the appearance of being powdered, the sailors humorously style it “the barber.” Such of the frost-rime as is dislodged from the rigging whenever the ship is tacked, covers the deck to a considerable thickness, and, when trod upon, emits an acute sound, resembling the crushing of fine particles of glass. The cause of this phenomenon, which generally is not observed until the cold is reduced to 14°, may perhaps be similar to that producing rain, and may be explained according to Dr. Hutton’s theory. An aqueous vapour, consisting of very minute frozen particles, sometimes occupies the lower regions of the atmosphere in temperate and frigid climates, during frosty weather, and is deposited on the ground, on surfaces of ice, or almost any other substance with which it comes in contact. This vapour seems to be of the nature of _hoar-frost_; it generally appears in the evening, after a bright sunshiny day.