The Growth of Yeast in a Magnetic Field

In regard to magnetism, all substances may be divided into three classes, namely, ferro-, para-, and diamagnetic. Ferro-and para- magnetic substances offer less resistance (reluctance) to the lines of force of the magnetic field than the air, therefore the lines of force tend to be drawn into the substance. A sliver of such material tends to turn so that its long axis is in the direction of the field. In a heterogeneous field the material will be moved toward the stronger part of the field. These character-istics are easily observed in iron, but the motion of paramagnetic substances is so slight that it can be detected only by microscopic methods. Diamagnetic substances, contrary to the first two classes, offer more reluctance to the magnetic field than does the air. A sliver of such material tends to turn across the lines of force, and to be forced out of a heterogeneous field. Of the few papers proving an influence of a magnetic field upon living organisms, the most extensive refer to protoplasmic streaming. If this is an electrical phenomenon, it should be affected by a magnet. After several investigators had failed to find an effect, Ewart (1903) by using a stop-watch and an ocular micrometer, finally detected a retardation of the rate of stream-ing. He also found that certain elongated plant cells were paramagnetic; they swung in the direction of the applied mag-netic field. Ssawostin (1930a) confirmed Ewart's findings, using algae. He could accelerate or retard the rate of streaming, depending upon the direction of the applied field. He attributed retarda-tion to friction between the protoplasm and the cell walls,