Page:Popular Science Monthly Volume 51.djvu/732

716 chemical school of the city of Paris. He was a member of the Academy of Medicine and the Academy of Sciences. His principal works were on the application of chemistry to animal physiology, coloring substances, fermentation (in the International Scientific Series), and the Traité de Chimie Générale, in seven volumes.

Primitive Drills.—We all know how difficult it is, even with the best tools we have, to bore a correct hole by hand in a hard substance. Vastly more difficult must this have been with primitive men, who had no tools except flints and bones and sticks. Yet, as Mr. J. D. McGuire observes in his study of the Primitive Methods of Drilling, the earliest remains of man are found associated with implements of his manufacture in which holes have been artificially perforated, the implements consisting generally of bone, ivory, or shell. During the cave period man had the implements called "batons of command," the use of which is unknown, which were bored with extreme care from reindeer horn, and are often carved with representations of animals or of man, often artistically done. These men could only fashion the rudest implements from chipped stone. At later periods of development beads of shell and stone were made of shapely forms and evenly perforated. Of such are the Indian wampum beads, which, according to Lawson's History of North Carolina, they managed "with a nail stuck in a cane or reed. Thus they roll it continually on their thighs with their right hand, holding the bit of shell with their left, so in time they drill a hole quite through it, which is a very tedious work." This describes the most primitive form of drill, except that men had not yet advanced to the nail. They used flints or bones or sticks, re-enforced with sand. Mr. McGuire's presentation of objects perforated with this sort of drill exhibits some spocimensspecimens [sic] of fine work done in hard stone and applied to various purposes. The next development is the strap drill, in which a string or cord is wound around the stick, and when pulled back and forth produces corresponding alternations in the motions of the drill, and adds considerably to its power. To this was added a bow, the pulling and relaxing of which maintained the revolution of the instrument. An improvement on this was a disk, the momentum of which carried on the motion of revolution, and rewound in an opposite direction the string which had been unwound. When the bow was arranged so as to have an upward and downward motion on the stick, the pump drill was constituted, an instrument differing essentially from all other boring tools, relatively easy to work, which has been widely distributed. The Egyptian monuments bear frequent representations of the use of the bow and disk drills under different forms and with various modifications. The Egyptians, however, had copper and iron.

Birds and their Songs.—Whether birds inherit their song or learn it by imitation has been the subject of experiments which M. Flamel describes in La Nature. We know already that some species take up the songs of others, but it had not been determined whether they ever learned them at the expense of their native song. One of M. Flamel's correspondents had a sparrow, "brought up by hand," which, when put into a cage with finches and canary birds, took up the songs of all its companions, repeating them perfectly; and then, some captured crickets having been placed near it, adopted their chirp too, but never sang like a sparrow. Another correspondent was told by a gamekeeper of two linnets which he had taken from the nest when they were very young and kept at his home in a wood where there were no other birds of their species, but nightingales were abundant. The birds sang like nightingales. Of the somewhat varied repertory of songs of a certain species of linnet, this correspondent asserts that the songs are severally peculiar to certain well-defined localities. All the individuals in one of these districts have the same songs and the same number of songs, so that the fanciers in the city where he lives are acquainted with the songs of the several stations around and know just where to go to get birds to their liking. It follows from this that some birds, at least, learn their songs by imitation.

Sunlight and Bacteria in Rivers.—In view of the destructive effect of sunlight, especially of the blue to the ultra-violet rays,