FURTHER OBSERVATIONS ON THE EFFECT OF HIGH FREQUENCY SOUND WAVES ON LIVING MATTER

Abstract

A study has been made of the effects of sound waves of 400,000-2.25 million per sec. frequency on living cells and tissues mounted on a quartz crystal on the stage of a microscope. The crystal is made to vibrate (by reversal of the piezo-electric effect) by placing it in a high-potential, high-frequency electric field. The whirling of chloroplasts in Elodea leaves as affected by various factors (air bubbles, amount of water, interference patterns, frequency of waves) is discussed. Great intensity causes emulsification of chloroplasts. In Amoeba proteus and A. dubia granules rotate on their axes. High intensity causes whirling of protoplasm and rupture of pellicle. In sea-urchin and starfish eggs the jelly and membrane are torn and the cells cytolyze. There is no movement of materials inside the eggs unless they are made less viscous by treatment with dilute sea-water. Asters are unaffected and cleavage furrows come in normally even while being rayed. There was no stimulating effect on the gill cilia of Mytilus, pigment cells of Fundulus, abdominal muscle of the frog, luminescence of Mnemiopsis, or the heart beat of Fundulus embryos. In fertilized Fundulus eggs the granules and oil dance and the yolk is stirred up, but they develop normally. These sound waves can be used to stir up the inside of the cells and to determine viscosity, but quantitative results are difficult because of the complexity of interference patterns and resulting uncertainty of intensity.