Page:Popular Science Monthly Volume 1.djvu/397

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cial and temperate conditions, but associated with the great continental ice-sheets; second, a temperate climate with removal of the ice-sheets from low grounds; third, a period of subsidence, with temperate climate, and much denudation of moraines; fourth, a period of emergence, with arctic conditions, floating ice dispersing erratics, and deposition of clays with arctic mollusca; and, fifth, a period of local glaciers in Britain and Ireland, with gradual amelioration of climate.

Dr. Cobhold says that, when once the trichina has gained admission to our muscles, all hopes of dislodging it are at an end; but, if a person suspects that he has eaten diseased or trichinized meat, he should lose no time in seeking assistance. Immediate advice, followed by suitable remedy, might be the means of saving his life, whereas a few days' delay would perhaps prove fatal. While the worms are in the intestinal canal, we can get rid of them; but, when once the trichinal brood migrates into the flesh, no means are known by which their expulsion can be effected.

A Berlin lithographer, after years of study, is said to have at last succeeded in producing a paper for printing money which it is impossible to imitate. The color of the paper is the only secret on which the invention rests. The inventor says the colors cannot be chemically analyzed; with the magnifying-glass they can be distinguished from all other colors, and in their quality as colors they cannot be imitated by photography, nor in any other way.


According to the observations of a writer in Land and Water, the time required for fish-eggs to hatch varies greatly with different seasons. He states that in 1869 ova from the trout hatched in 55 days, in 1870 they were 92 days hatching, in 1871 95 days, and in 1872 they hatched in 82 days. With the exception of temperature, the conditions were identical in the different years. The first year there was no frost, and the ova were in a house with a glass roof, and consequently at a high temperature. The second and third years there were long frosts after the eggs were placed in the boxes, and this year there was also some frost.

Catoptric lamps, or lamps provided with reflectors, are being introduced in London for lighting the streets. The reflectors are so placed in the top of the lamp that those portions of the light ordinarily passing skyward are made to illuminate the foot-ways. The light is evenly distributed; and from the same jet, as shown by the photometer, three times as much illuminating power is obtained as by the old-fashioned lamp.

Prof. Pepper, of ghostly fame, is giving in London a popular scientific entertainment, followed by a lecture on "spiritualism." The professor announces himself as ready to give all the "manifestations" usual at "spirit séances". He "tips" the tables, and "scratches" the same, with all the airy grace of a disembodied sprite. The "hand of glory" is to be seen at his entertainments, and a violin is made to float in the air. Mr. Pepper has not yet perfected his arrangements for "floating" himself à la Home, but that feat is "on the bills," and will be performed in a few days. The means by which he performs these marvels he keeps secret at present, but promises to publish them after a few months.

The use of rubber plates and rings, for making connections between steam and other pipes, is often attended with much annoyance, owing to the leakage of the joints. This may be prevented by employing a cement prepared by dissolving shellac in ammonia. The pulverized gum-shellac is soaked in ten times its weight of strong ammonia, when a slimy mass is obtained, which in three or four weeks will become liquid without the use of hot water. This fastens well both to the rubber and to the metal or wood, and becomes, by volatilization of the ammonia, hard and impermeable to either gases or fluids.

Coloring Matter in Fungi.—Mr. H. C. Sorby has determined the existence of at least 30 distinct coloring substances in fungi. The majority contain at least two, and many of them several, different kinds. Twenty of these have such well-marked optical qualities that they could be recognized without difficulty in other plants, but only one of them, a fine orange-color, is known to exist in any plant not a fungus. As far as Mr. Sorby's observations extend, there is little or no specific agreement between the substances found in fungi and those met with in algae and lichens, though the two latter orders are closely related in this respect.—Science Gossip.

Prof. Herman, in a paper published in Pflüger's Archiv, states that living muscle offers very much greater resistance to an electric current passing in a direction across