43 



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 sur- 

 face 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 inci- 

 dence. The excess of pressure diminishes 

 as the strata grow deeper. The pressure de- 

 termined by the wind increases with the 

 grossness of the particles and as the struc- 

 ture is grumelous. 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 occa- 

 sions 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 influ- 

 ence 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 propor- 

 tion to its velocity and the magnitude of the 

 angle of incidence. 



Behavior of Different Trees to Light- 

 ning. The resistance of different trees to 

 the electric spark has been studied by M. 

 Jonesco Dimitrie, who placed pieces of sap- 

 wood 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 sufiicient with black 

 poplar and willow. Ssmilar results were ob- 

 tained 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 " fat- 

 ty " 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 to- 

 ward 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 con- 

 ducting power of the tree itself. These re- 

 sults are in harmony with what has been ob- 

 served 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 associ- 

 ated 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 ac- 

 cent ; 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 distinc- 

 tive pronunciations affecting vowels or con- 

 sonants ; but independently of these he will 

 use in his phrases and sentences a combina- 

 tion of tones a tune which alone would 

 suffice to suggest the nationality of the 

 speaker. All national speech has its charac- 

 teristic 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 inter- 

 esting paper, which he read before the Mod- 

 ern Language Association last December, to 

 the analysis of these " speech tones." He 

 especially discusses the tones of the Chinese 

 language. 



Bacteria in Bntter-niaking. In a bulle- 

 tin 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- 



