Page:Popular Science Monthly Volume 45.djvu/446

This page has been proofread, but needs to be validated.
430
THE POPULAR SCIENCE MONTHLY.

the same hour every night'; regularity in this matter is a powerful hypnotic.

 

Effects of Wind on Soil.—Investigations by M. J. A. Hensele show that when the wind bears in an acute angle upon the surface of a soil it produces a pressure of the air of the soil that increases with the speed of the wind and the increase of the angle of incidence. The excess of pressure diminishes as the strata grow deeper. The pressure determined by the wind increases with the grossness of the particles and as the structure is . The wind provokes a diminution of richness in carbonic acid of the air of the soil, which becomes greater with increase of velocity. It also increases the evaporation of water from the soil. Wind striking the ground at an angle occasions an evaporation of more unequal force than when it blows horizontally. Richness in moisture has much influence in retarding evaporation, while elevation of temperature quickens it. The wind has no direct influence on the capillary ascent of water in the soil, but only acts indirectly by favoring evaporation and thus provoking a movement of water toward the surface as long as there is much of it in the soil. The temperature of the soil is depressed by wind in proportion to its velocity and the magnitude of the angle of incidence.

 

Behavior of Different Trees to Lightning.—The resistance of different trees to the electric spark has been studied by M. Jonesco Dimitrie, who placed pieces of sapwood of beech and oak in the way of the spark of a Holtz electrical machine. The spark passed through the oak after one or two revolutions of the machine, while twelve or twenty revolutions were required to give it force enough to pass through the beech. Five revolutions were sufficient with black poplar and willow. Similar results were obtained with heartwood. The presence of water had no influence on the resistance, but richness in fat was an important factor. "Starchy trees," poor in fat, like the oak, poplar, willow, maple, elm, and ash, opposed much less resistance to the spark than "fatty" trees, like the beech, chestnut, linden, and birch. The pine, which is rich in oil in winter and poor in it in summer, shows a corresponding difference in behavior toward the spark at those two seasons. In the "starchy" trees the living wood was harder to strike with the spark than the dead wood. The bark and foliage are poor conductors in all the trees, but this is of little importance as compared with the conducting power of the tree itself. These results are in harmony with what has been observed as to the relative frequency with which trees of these several species are struck by lightning. The author found also that station and soil affect the liability of trees to be struck. The vicinity of water augments the danger. Isolated trees seem more liable than those which are massed. All species of trees may be struck when the electric tension is high.

 

Speech Tones.—Attention is called by Alexander Melville Bell to the tones associated with speech as a subject deserving scientific investigation. These tones are generally spoken of as accents. "Thus we say of a stranger that he has a foreign accent; or we may define the peculiarity and say he has an Irish, a Scotch, a French, a German, a Western, or a Southern accent. He may or may not add to this some distinctive pronunciations affecting vowels or consonants; but independently of these he will use in his phrases and sentences a combination of tones—a tune—which alone would suffice to suggest the nationality of the speaker. All national speech has its characteristic tune. This is especially noticeable in dialects of the same language. We are but little cognizant of our own habitual tunes, but we are at once sensible of any marked deviation from them in the speech of others." The author devotes a very interesting paper, which he read before the Modern Language Association last December, to the analysis of these "speech tones." He especially discusses the tones of the Chinese language.

 

Bacteria in Butter-making.—In a bulletin of the Storrs Agricultural Experiment Station, Connecticut, on the Ripening of Cream by Artificial Bacteria Cultures, the chief object of the ripening of cream is shown to be to produce the butter aroma. This aroma, though very evanescent, con-