CURIOSITIES OF SCIENCE AND NATURE.
GOLD-BEATERS can, by hammering, reduce gold leaves so thin that 282,000 must be laid upon each other to produce the thickness of an inch, yet each leaf is so perfect and free from holes that one of them, laid on any surface, as in gilding, gives the appearance of solid gold. They are so thin that if formed into a book, twelve hundred would occupy the space of only a single leaf of common paper; and an octavo volume of an inch thick would have as many pages as the books of a well-stocked library of fifteen hundred volumes, with four hundred pages in each. Still thinner than this is the coating of gold upon the silver wire of what is called gold lace. Platinum and silver can be drawn in wire much finer than human hair. A grain of blue vitriol or carmine will tinge a gallon of water so that in every drop the color may be perceived. A grain of musk will scent a room for twenty years, and will at that period have lost little of its weight. A burning taper uncovered for a single instant, during which it does not lose one-thousandth part of a grain, would fill with light a sphere four miles in diameter, so as to be visible in every part of it. The thread of the silk-worm is so small that many of them are twisted together to form our finest sewing-thread. But that of the spider is finer still, for two drachms of it by weight would reach four hundred miles. In water, in which vegetables have been infused, the microscope discovers animalculæ of which many thousands together do not equal a grain of sand; and yet nature, with a singular prodigality, has supplied many of these with organs as complete as those of the whale or of the elephant, and their bodies consist of the same ultimate substance as that of man himself. In a single pound of such matter there are more living creatures than of human beings on the face of the globe.—Selected.