NOTES OF SCIENCE AND DISCOVERY.
A NEW MOUSE-TRAP.—Professor Alsnel says that sticky fly-paper used in summer to catch flies is said to make an excellent mouse-trap. Lay a sheet of it in front of the hole from which the mice emerge, and it will hold them fast until you capture them. The same paper can be used again and again. This is better than poisoning them, allowing them to retreat into their holes and there decay offensively. XYLOLITH.—Dr. Otto Lehnig has produced a substance which he calls "xylolith," or "wood-stone," which he thinks will prove a very useful building material in the near future. It is made of a mixture of magnesia and sawdust, subjected to a high temperature and great pressure. It can be cut with tools, but does not burn or absorb moisture. A MUSICAL SPARROW.—An interesting account of the musical accomplishments of a sparrow is given in La Revue Scientifique by M. Mingaud. He captured the sparrow soon after it had been hatched, and fed it by hand until it could care for itself. Then he placed it in a cage containing a chaffinch, a goldfinch, and two canaries. After a time the sparrow learned to warble like the finches and to trill like the canaries, the imitations being so perfect as to deceive the ear. Some crickets having been placed near the cage containing the sparrow, the latter began to imitate their cry, and even after the crickets had long been dead the sparrow remembered its lesson and continued to repeat the cry. Singularly enough the sparrow never utters the peculiar squalling cry of its own species, having been removed from its nest too early apparently to have learned it. THE WONDERFUL HUMAN MACHINE.—The human body is an epitome in nature of all mechanics, all hydraulics, all architecture, all machinery of every kind. There are more than 310 mechanical movements known to mechanics to-day, and all of these are but modifications of those found in the human body. Here are found all the bars, levers, joints, pulleys, pumps, pipes, wheels and axles, ball and socket movements, beams, girders, trusses, buffers, arches, columns, cables, and supports known to science. At every point man's best mechanical work can be shown to be but adaptations of processes of the human body, a revelation of first principles used in nature.