Page:Popular Science Monthly Volume 32.djvu/739

Rh describes the effects of the operations of the marmots in modifying the surface of the Siberian steppes as important. Their heaps of earth cover hundreds of square miles, and each one of them represents at least two cubic metres of earth removed, or about 30,000 cubic metres brought to the surface on each square kilometre.

survey and last census of India show that the area of the peninsula of Hindostan is 1,382,624 square miles, and the population 253,891,821. Although immense tracts of country are annually cultivated, ten million acres of land suitable for cultivation have not as yet been plowed; and one hundred and twenty million acres are returned as waste lands.

Director of the Aëronautic Union of France, has found a satisfactory varnish for textile materials. It is described as being of great flexibility, as containing no oleaginous base, and, while adding little to the weight, as conferring great impermeability. It is well adapted for balloons, marine cordage, sails, tents, and similar structures; is suitable for paintings and wainscotings; is exempt from moldiness; can be exposed to very varied temperatures without alteration; and furnishes sub-products which can be utilized for coating walls, railway-sleepers, etc.

offers as a better explanation than the old one of the zigzag course of lightning, that owing to variations of moisture the conducting power of different portions of air is variable, and the electric discharge follows the course of least resistance.

at the Winter Palace of the Czar at St. Petersburg indicates that the electric light injures the exotic plants used for the decoration of the rooms by causing the leaves to turn yellow, dry up, and fall off. The experiments of Dr. Siemens led him to a different conclusion, but his greenhouse was heated by the waste steam from the engine driving his dynamo, and this perhaps was of beneficial effect sufficient to counteract the mischief done by the light.

effective composition for a "hand-grenade" tire-extinguisher is, common salt, 19·46; sal ammoniac, 8·88; water, 71·66; or 20 pounds of salt, 10 pounds of sal ammoniac, and 7 gallons of water. The flask should be of thin glass, so that when thrown with force against any object, it will fall to pieces. The grenades, costing but little, can be distributed freely all over the premises to be protected; and, should a fire occur, break a bottle or several bottles over it, and the disaster will probably be averted.

has observed, by experiment, that hot baths induce a loss of weight caused by the sweating, which lasts for about twenty-four hours. It is compensated for by increased drinking and diminished urinary secretion. Baths of dry hot air provoke a sweat that ceases on coming out of the bath, while the perspiration provoked by warm-water baths and warm moist-air baths lasts frequently for an hour after the bath is over. The nervous incidents of the bath, such as the acceleration of the pulse and of respiration, make their appearance before the central temperature exhibits any elevation.

M. B., relates in "The Lancet" the case of a family whom he had attended, who were poisoned from eating bread in which mold had developed itself. Every member who had partaken of the loaf inordinary quantity had been made ill; one member who had merely eaten a small piece, felt uncomfortable; those who did not eat any remained well. The symptoms were diarrhœa and pain in the epigastrium. The author suggests from this experience, that it is possible that we may have in undetected diseased bread an important factor in the causation of diarrhœa which we would not readily suspect.

whose plants mysteriously sick. en and die out, may learn from the experience of Dr. J. W. L. Thudicum, as related by him to the London Society of Arts. He watered a frame of flourishing young wallflowers, the ordinary tap being dry, with water of at least suspicious purity from another tap. The plants were soon infected with a fungus, and in a short time the frame did not contain a healthy, hardly a living plant. For two summers the mignonettes in a conservatory were destroyed by a root-fungus which distorted the plants and made them sickly and short-lived. The only way in which this parasite could be got rid of was by destroying the earth and all wooden boxes by fire, and growing no mignonette in the conservatory for two years.

made last year a successful and satisfactory exhibition of his process for softening water by means of the material called "anti-calcaire." Steam-boilers which had already become slightly incrusted with lime, were worked for two years with water softened by anti-calcaire without attention. When opened, they were wholly free from incrustation, showing that the material had not only prevented the effect taking place, but had also destroyed what incrustations had already accrued.

of Specimens of poisonous fishes is shown in connection with the exhibition recently opened in Havre, France.