Magnetic Induction in Iron, and Other Metals #262338

A reminder of how far the subject still is from finality comes, as the last pages are passing through the press, in the announcement by Prof. J. J. Thomson of his demonstration that iron continues to be strongly susceptible to magnetisation by such rapid alternations of magnetic force as occur in a Leyden-jar discharge and that the damping-out of the electric oscillations when the discharge traverses a coil with an iron core proves magnetic hysteresis to play an important part, notwithstanding the excessive frequency of the reversals. Independent experiments made by Prof. Trowbridge point to the same conclusion. Prof. Thomson's use of vacuum-globes without electrodes as induction secon darles opens up new possibilities of magnetic research, which he has himself been the first to turn to account.