Page:Popular Science Monthly Volume 13.djvu/136

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THE POPULAR SCIENCE MONTHLY.

Snake-Affection.—Most people will prefer knowledge at second hand of the playfulness and affection of snakes, to personal tests of the existence of such qualities. Not so a correspondent of Land and Water, who, having got possession of a harmless snake of the species Natrix torquata about twenty-eight inches in length, adopted it as a pet. This snake took great pleasure in passing in and out again and again between the fingers of its master. It was only necessary to hold the hand in the open box, when he would at once commence to glide between the fingers, always turning round sharply the instant its tail was free, and resuming its journey in the contrary direction. The process of shedding the skin is worthy of observation. The snake lies in a sluggish state for several days. The bright eyes become dull and fishy, and the skin loses its glossy smoothness. In time a slight break appears to run in the line of demarkation between the mucous membrane of the mouth and the outer skin, along the edge of the lips. In a few hours the crack appears to widen, and the skin to dry and curl over at the edges. Soon after this, in the present instance, the snake passed through a wisp of straw provided for this purpose in his box, and the skin was stripped off in one piece. The animal was now as active as a kitten, and as hungry. He quickly swallowed a fog, whose cries were heard after it had passed into the snake's stomach.

 

A Magnetized Spider.—In a communication to the Academy of Natural Sciences of Philadelphia, Dr. John Vansant treats of the influence of magnetism on living organisms, and describes at length one experiment with a spider, which was killed by the magnetic emanation. The magnet employed was a small steel one, of the U-shape, the legs of which were about two and one-half inches long by one-half inch wide and one-sixth inch thick, the distance between the poles being about one-quarter inch. Having noticed a small spider actively running along the arm of his chair, he brushed it off upon the carpet, where it began to run, but was somewhat impeded by the roughness of the fabric. He now slid the magnet along the carpet, following after the spider, till it was between the poles. The animal almost instantly stopped, and in a few seconds was motionless; but, at the end of two or three minutes, it began slowly to move its legs and elevate and depress its head. At the end of five minutes the spider was quite still. After the lapse of ten minutes Dr. Vansant covered both spider and magnet with a tumbler. On the expiration of two hours, he removed the glass and observed the spider with a magnifying-lens. It was apparently dead. The author states that he has killed spiders and other small animals, as worms and insects, as well as some plants, by magnetism, at various times during the past eight years, but never before succeeded in destroying the life of a spider so quickly, and without touching it frequently, though lightly, with the magnet. In the present instance he did not touch the animal at all.

 

Waste of the Locomotive-Whistle.—Persons residing in the country near any of the great railway lines will heartily approve any effort made toward suppressing the nuisance of locomotive-whistles. A writer in the Railroad Gazette remarks as follows on the wastefulness of this practice: "A simple toot or two," he writes, "in cases of emergency, to warn some one from the track, or as a signal for brakes, would seem to be the only legitimate use of steam in the way of whistles. And yet, of the twenty or more trains which daily pass my residence, I notice that nearly one-half make a regular practice of blowing their whistles some twenty rods at a time, and some half a dozen times within as many miles; and their safety-valves also seem to be at work most of the time. It would be interesting to know exactly what percentage of the fuel is wasted in this way. If the coal-bunks upon their tenders were made so as to let a bushel of coal drop on the track every ten miles of their progress, the waste would then become so manifest, no doubt, that it would be attended to at once. If one train can be run without the use of the safety valve or whistle, another can be so run, with the exercise of an equal care and vigilance on the part of the engineer and fireman. This matter of waste at the safety valve and whistle seems to rest entirely with the men upon the foot-board of the engine; and, as they prize their good standing as engineers and firemen, they should attend to it."