observation its uses are without limit; and as an article of mere embellishment, there is no form into which it may not be moulded, or no object of luxury to which it may not be adapted. Yet this agent of universal utility, so valuable and ornamental in its applications, is composed of materials which possess in themselves literally no intrinsic value whatever. Sand and salt form the main elements of glass. The real cost is in the process of manufacture. CURIOUS PROPERTIES OF GLASS. Out of these elements, slightly varied according to circumstances, are produced the whole miracles of the glass-house. To any one, not previously acquainted with the component ingredients, the surprise which this information must naturally excite will be much increased upon being apprised of a few of the peculiarities or properties of glass. Transparent in itself, the materials of which it is composed are opaque. Brittle to a proverb when cold, its tenuity and flexibility when hot are so remarkable that it may be spun into filaments as delicate as cobwebs, drawn out like elastic threads till it becomes finer than the finest hair, or whisked, pressed, bent, folded, twisted or moulded into any desired shape. It is impermeable to water, suffers no diminution of its weight or quality by being melted down, is capable of receiving and retaining the most lustrous colors, is susceptible of the most perfect polish, can be carved and sculptured like stone or metal, never loses a fraction of its substance by constant use, and, notwithstanding its origin, is so insensible to the action of acids that it is employed by chemists for purposes to which no other known substance can be applied.