AUGUST, 1950 0
A CONVENIENT DEMONSTRATION OF DIAMAGNETISM ERICH A. O'D. TAYLOR Portsmouth Priory School, Portsmouth, Rhode Island
DIAMAGNETIC forces are generally recognized; the diamagnetism of certain elements is indicated frequently on charts of the Periodic Table. Yet this property is not commonly demonstrated at the lecture table. We have found that a crystal of bismuth about a quarter of an inch long furnishes admirable evidence of this property. Crystals can easily be knocked out of a suddenly cooled bismuth mass. The crystals, however, are so small that they do not form a satisfactory classroom demonstration by themselves. I have found that, by mounting such a small bismuth crystal on a square of Scotch tape, which also adheres to a length of thread; and, by the same means, fastening a colored hroomstraw to the thread higher up, a typical Alnico demonstration magnet will be sufficient to give a satisfactory indication. Rotating the magnet while the crystal is freely suspended shows the persistence with which the crystal remains directly aeross the magnetic field.
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