THE COLORADO MEDICAL JOURNAL. and other national airs are borne, in the heat of the conflict, to the excited battalions, or, when, under the Gothic vault, the sad "Stabat Mater" pours out its mournful notes, it is the vibrations which effect us by speaking a mysterious language. Now, all in nature is Now, all in nature is motion, vibration and harmony. The flowers of the garden sing, and the effect which they produce depends on the number and agreement of their vibrations relatively to those which emanate waves which come from different sides, so the atom of the ether undulates under the influence of light and heat; the atom of air undulates under the influence of sound, and the planet and satellite circulate under the influence of gravitation. Harmony is everything. To the eye ciple, nothing is more interesting than of the person acquainted with the printhe crossing of waves of water. By their interference the surface of inter Fig. 2. The Chladni Figures from Dr. Mount Bleyer's article on "Voice Pictures and the Wonders of Sound-Force." I actly the same note, the combination of the two vibrations rendered visible on the screen by the little mirrors that inscribe them in lines of light, produces a perfect circle; that is to say, the simplest geometrical figure; as the amplitude of the vibrations diminishes, the circle flattens, becomes an ellipse, then straight lines. This is the first row of Fig. 3 in which the number of vibrations is in the absolutely simple ratio of 1 to 1. If, now, one of the two tuning-forks is exactly an octave from the other, the vibrations are in the ratio of I to 2, since every note has for an octave a number of vibrations exactly double, and instead of a circle it is an 8 which is formed and modified as we see in the second row. If we take the combination of two tones of 1 to 3, say do with the sol of the octave above, we obtain the figures of the third row. If we combine 2 to 3, as do and sol of the same octave, we produce those of the fourth row. The union of 3 with 4, of sol with the do above, gives the fifth series. What is most curious is, that in the complete figures (those of the middle of each series) the number of summits in the vertical direction and in the horizontal direction indicates the ratio of the vibrations of the tuning-forks. Yes, in everything and everywhere numbers rule the world. Many curious experiments among those made by Dr. J. Mount Bleyer (Voice Pictures), and those of Miss Watts Hughs are also evidences of the facts just spoken of.' Why, however, seek in scientific an alysis testimony to the harmony which nature has shed over all her works? Although it may be necessary for us to rise to the ideal of music to contemplate the beautiful color of the sky or the splendor of the setting sun; we may on a dull winter-day, in the grey and monotonous hours when the snow falls in innumerable flakes, examine with the microscope some of the flakes and the geometrical beauty of these light crystals (Fig. 4) will fill us with admiration. As Pythagoras said, “God works everywhere by geometry." The velocity of light has been approximately known for more than two centuries. The honor belongs, however to the modern physicist, Prof. Harkness, who has made the most correct calculation, in 1891, and found it. to be 186,337,000 plus or minus 49.723 miles per second. Thus, when we see an eruption shoot out from the solar limb, eight minutes have elapsed since the event occurred. When we see a satellite of Jupiter lose its light, it is at least thirty-four minutes since the eclipse took place. When we observe Neptune we see it as it was four hours previous. When we look at a star, we see it, but not as it was at the moment the luminous ray left it— that is to say, four years ago with reference to the nearest, and ten years, twenty years, fifty years, one hundred, a thousand, ten thousand years, according to the distance. Likewise, a transcendant eye placed at these successive distances would now see the earth as it was four years, ten years, or more ac 'Journal of Eye, Ear and Throat Diseases. Baltimore. Voice Pictures; or the Wonders of Sound-Force; Their Production and Their Photography. Sept. and Oct., 1904. cording to the distance. Light makes the past an eternal present. Such is the progressive transmission of light. But how shall we represent the action of the sun in the production of this light? Let us remark, first, that the radiant. On the other hand, we know that heat is nothing else than a mode of motion; it is the motion of the molecules in rapid vibration which is felt as heat.' Light is otherwise but a vibration. There is no solid matter, properly so called, and this is a fact no less worthy Fig. 4.-Snow Flakes-Showing their Geometrical Forms. star sends us heat at the same time as light, and that very often the two species of rays are mixed up. Every-day experience shows us, also, that heat raised to a certain degree becomes light. of attention than that of astronomical magnitudes and motions. In the densest mineral, in a piece of iron, of steel, of platinum, the molecules do not touch. Cohesion, which is the attraction 'Let us strike a piece of iron. The muscular motion of the arm is transmitted to the molecules of the iron, which are in a state of invisible motion that we call heat. Friction produces heat, and this was the first source of fire among the ancients. Thermo |