Page:Popular Science Monthly Volume 43.djvu/300

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288
THE POPULAR SCIENCE MONTHLY.

immense numbers of individuals, and living in various media, capable of developing at the freezing point. One of them, a sea-water species, produces phosphorescence at that temperature. It is well known that to preserve meat and other articles of food successfully it is necessary to employ a much lower temperature than that of the melting of ice, and experience has further shown that this is best done when the atmosphere is deprived of moisture.

Electric currents were proved many years ago to exist in plants; and Kunkel was led to think, by his experiments, that they were caused by the mechanical process of water-motion, set up on application of the moist electrode. A new investigation of the subject has been made by Herr Haaske, and he concludes that it is unquestionable that changes of matter of various kinds are concerned in the production of the electric currents, especially oxygen-respiration and carbonic-acid assimilation; and that while water movements may possibly share in their production, their share is certainly only a small one.

Mr. Kepamath Basu has observed that under the influence of enlarged education and refinement, tattooing and the use of red paint on the forehead and crown are diminishing among the women of Bengal. These fashions still persist in the Northwest Provinces, along with the insertion of thick and heavy wooden plugs in the lower lobes of their ears.

A specimen of ruthenium, weighing two kilogrammes, prepared by M. Joly, was recently exhibited in the French Academy of Sciences. The metal is very hard and brittle, having a specific gravity of 12, and melts at the temperature of the electric arc. It is usually found associated with iridium, palladium, rhodium, and osmium, in platinum ores.

Herr Du Bois-Reymond has shown, in a communication to the Physiological Society of Berlin, that a sensation of heat follows the immersion of the hand in a receiver containing gaseous carbonic acid. A like effect is produced by other gases which do not enter into the composition of the air. The heat sensation may be compared with that produced by a temperature of 68° Fahr. in the air. The phenomenon results from a stimulation of the nerves sensitive to heat.

Experiments are described by Herr Wesendonck, the object of which was to determine whether electrification is produced by the friction of gases. While ordinary air gave considerable charges, negative or positive, according to the adjustment of the apparatus, no electrification was produced when the air had been previously freed from dust and moisture. Oxygen behaved in the same way. Carbonic acid, evaporated from the liquid state, imparted a strong positive charge, which was, however, reversed as soon as the cold led to the precipitation of watery vapor. Ordinary atmospheric dust was found to electrify the brass negatively, and the charge was increased by previous drying. It seems, therefore, that pure gases are incapable of producing electrification by friction, and that the effects observed are conditioned by the presence of solid or liquid particles.

An account of a thunderstorm in which the rain was mixed with live land mussels, which is said to have occurred at Paderbom, Germany, in August, 1892, is published in Das Wetter. A yellowish cloud attracted the attention of several people, both from its color and the rapidity of its motion, when suddenly it burst. A torrential rain fell with a rattling sound, and immediately afterward the pavement was found to be covered with hundreds of the mussels.

Dr. E. Lewis Sturtevant has presented to the Missouri Botanic Garden, St. Louis, his entire botanical library, which is particularly rich in pre-Linnæan works.

The question of evaporation from the surface of snow is discussed in a Russian meteorological journal by M. A. Müller, of the Observatory of Ekaterinberg. Authors who have previously written on this subject, including Nuckner, Woeikoff, and others, have not been agreed as to whether the evaporation exceeds the condensation from the air in contact with the snow. The method usually adopted has been to compare the temperature at the surface of the snow with the dew point, and assume that if it is superior, evaporation, if inferior, condensation, takes place. M. Müller's observations were made from December 21, 1890, to February 28, 1891. His conclusion is that, according to the method adopted, evaporation is superior to condensation in the proportion of 73 to 27.

The report of a parliamentary committee on the plague of voles in Scotland shows, on the authority of early Celtic chroniclers, that as early as the year 896 Ireland was devastated by a plague of "vermin of a mole-like form, each having two teeth," which "fell down from heaven," and were driven out only "by prayer and fasting." There is also a plague of voles in Thessaly (a Grecian land), and the Mohammedans there have sent to Mecca for some holy water.

 


OBITUARY NOTE.

The Rev. F. O. Morris, of Yorkshire, England, a well-known popular writer on natural history, died April 10th, aged eighty-two years. Among his many books were A History of British Birds, in six volumes, and Natural History of the Nests and Eggs of British Birds.