Page:Popular Science Monthly Volume 32.djvu/152

 "Indifferent," is ejaculated at each bead, till the big terminal one is reached, and that decides the question. Answers are given in conversation, bargains are made or refused, and serious acts are undertaken under the guidance of this formula. Another way is to thrust a knife into the leaves of the Koran or one of the poetical books, and be guided by what is found at the place. The diviners are real quacks, and gain their success by working on the fears of the people. The guilty party in a scandal or criminal inquiry in his nervousness is provoked to do some act that brings about his detection.

The Nature of Diatoms.—The curiously beautiful microscopic objects called diatoms can be found in the mud at the bottom of all pools of water. They were formerly regarded as animals, but are now classed among plants. Professor W. Mattieu Will-iams discovered their vegetable character thirty years ago by an observation which amounted to a demonstration. The white quartz pebbles in his aquarium became coated with a brown growth, caused by the development of these organisms, and at the same time evolved bubbles of gas. In the course of a few days he found an inch of the vertical space of the test-tube which he fixed to catch it filled with this gas, and it was proved by burning wood and other experiments to be nearly all oxygen. Animals expire carbonic acid, plants expire oxygen. Therefore the diatoms were plants.

A Rock-sculptured City.—Montpellier le Vieux is the name given to a curious city-like group of weather-sculptured rocks, which M. E. A. ilartel has described to the French Academy of Sciences. It is near Millau, in Auvergne, France, and about twenty-five hundred feet above the sea. It is composed of a mass of isolated rocks, averaging per-haps about two hundred feet in height, so similar to embattled towers that one group has been called the Citadel; around this mass are five depressions three or four hundred feet deep, of which one resembles an amphitheatre, a second a necropolis, a third a parade-ground, and another a regularly laid out city quarter with public monuments, gates, straight streets and intersections suggesting at once such places as Pompeii, Carnac, and Persepolis. The whole, occupying about five hundred acres, is surrounded by a rocky formation having the aspect of a wall three or four hundred feet high. The ravines under the bases of these walls might be regarded as fosses, and the scattered groups of rocks in the neighborhood as the fortifications of outer lines of defense.

Idiosyncrasies of Plants.—An English reviewer of a book by 5Ir. Charles Roberts, called "The Naturalist's Diary," mentions the idiosyncrasies of certain plants and animals as a feature to which more attention might be given. Thus, a quantity of seed taken from the same plant at the same time, and sown under the same conditions so far as possible, will nevertheless exhibit very great variation in the length of time required for germination. The fact enforces the circumstance that the same amount of aggregate temperature and of water-supply, the same conditions of soil, etc., do not necessarily imply corresponding identity of result. The same thing happens in trees. Every one knows how some individual horse-chestnut trees are year by year more precocious in their development than their fellows. It sometimes happens, too, that one branch of one tree is considerably in advance of the others. Some persons might call these cases exceptions, but they are hardly that. Since they are connected with the main body of habitudes by every possible gradation, they are to be considered as extremes rather than as exceptions, and therefore to be included in the making up of averages.



of the Natural History Society of Wisconsin, has been investigating the mental habits and peculiarities of wasps. On the question whether these insects have much sympathy with one another, he says: "To be sure, when we caught numbers of them, and painted them within the cage, they at once went to work to clean each other, and this shows that they have some desire to aid and comfort their friends. But we have often seen them continue to eat, with entire composure, near the body of one of their number that had just been crushed to death; and they frequently fall upon a dead relative, cut it up, and carry it into the nest to feed their young." 