Page:Popular Science Monthly Volume 18.djvu/153

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the electric current. If we put a light pressure upon the leaves of the condenser, the sound will be diminished in proportion as the pressure is increased, till it ceases. Reversing this experiment, M. Trève put a condenser into a Geissler tube, and brought the two poles of the inductive current of the Ruhmkorff coil to bear upon it through the electrodes of the tube. The tube was then connected with an air-pump. The condenser sounded as usual when the current was directed to it under the ordinary atmospheric pressure; as the air was withdrawn, the sound became more feeble, till, when a vacuum was produced, it ceased, and instead of it there shone a clear, bright light, sparkling like pearls, from the leaves of the condenser. It was not like the pale and vague light of the Geissler tubes, but something, he says, quite different, sharp and distinct—a condensed light.


Caves in Japan.—Professor Morse also described a number of artificially constructed caves which he had examined in various parts of Japan, giving sketches of them on the blackboard. These caves varied considerably in their design, but agreed in their general proportions, and were evidently intended as receptacles for the dead. They were excavated in soft rock on the sides of hills—the apertures small, and in some cases showing grooves for the adjustment of slabs of rock or other material to close them. The absence of remains in these caves could be explained by the fact that in earlier times outlaws and refugees often used them as places of shelter and residence, and laws had finally been passed by the governors of some of the districts, causing the caves to be filled up, or their entrances obstructed, to prevent their being used in this manner.



During an excursion to the White Mountains made in July, 1879, Mr. W. H. Pickering visited a moving mass of snow in Tuckerman ravine, which he describes as presenting many of the phenomena of an Alpine glacier, only on a greatly reduced scale. The surface of the snow was convex, being highest at the middle; where not exposed to the sun it was very hard, and differed from ice only in color. Stones previously plated upon the surface of the patch showed that the middle had a motion of about eight inches per day, the sides moving more slowly. In Mr. Pickering's opinion, it corresponds with the upper portion of a glacier, and might, perhaps, be called an incipient glacier.

An illustration of the fixedness of the characters of plants is shown from the analysis of specimens of the oleaginous Chinese pea {Soya hispida) from Hungary, China, and France. Only insignificant differences in composition were discovered notwithstanding the peas had grown in widely separated countries under very different conditions of climate and soil.

Professor Benjamin Peirce, F.R.S., LL.D., died in Boston October 6, 1880, aged seventy-one years. He graduated at Harvard College in 1829, was made Professor of Mathematics and Natural Philosophy in that institution in 1833, and Perkins Professor of Astronomy and Mathematics in 1842.

The minute organisms or microbes, which M. Pasteur has shown to be concerned in epidemics and contagious diseases, are so very minute that they may sometimes easily escape detection, especially in pure water. In such case they may be killed, without being deformed, by certain chemical agents, among which is osmic acid, and will sink to the bottom in such quantities as to admit of microscopic examination. The deposit may be examined after several hours (twenty-four or even forty-eight) if the water has been very pure. Coloring reagents mixed with dilute glycerine may also be used with advantage in the work.

A considerable number of the workmen engaged in the boring of the tunnel of St. Gothard were prostrated by a dangerous anemia. M. E. Perroncito, who has been investigating the causes of the disease, has found that all those who were affected by it were also troubled by certain species of parasitic worms, the mere presence of which was sufficient to account for the development of disease. This case is not an isolated one. Dr. Giaccone, a medical attendant of the St. Gothard company, states that a disease of identical character appeared during the boring of the tunnel of Fréjus.

An ostrich, long on exhibition at Rome, having been suffocated by thrusting its neck between the bars, there were found in its stomach four large stones, eleven smaller ones, seven nails, a necktie pin, an envelope, thirteen copper coins, fourteen beads, one French franc, two small keys, a piece of a handkerchief, a silver medal of the Pope, and the cross f an Italian order.