On hydrofluoric acid : on a momentary molecular change in iron wire : and on the development of electric currents by magnetism and heat / by G. Gore.

  • Gore, George, 1826-1909.
Date:
1869
Catalogue details

Licence: Public Domain Mark

Credit: On hydrofluoric acid : on a momentary molecular change in iron wire : and on the development of electric currents by magnetism and heat / by G. Gore. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    coil by continuously heating the iron wire. In several experiments, by employing twelve similar Grove’s elements as a double series of six intensity, an iron wire 1*56 millim. diameter was made bright red-hot; and by keeping the current continuous until the galvanometer-needles settled nearly at zero, and then suddenly disconnecting the battery, the needles remained nearly stationary during several seconds, and then went rapidly to about 10 : this slow decline of the current during the first few seconds of cooling was probably connected with the “momentary molecular change of iron wire ” during cooling which I have described in the preceding paper. The irregularity of movement of the needles did not occur unless the wire was bright red-hot, a condition which was also necessary for obtaining the molecular change. The direction of the current induced by heating the iron wire was found by experiment to be the same as that which was produced by removing the magnet from the coil; therefore the heat acted simply by diminishing the magnetism, and the results were in accordance with, and afford a further confirmation of, the general law, that wherever there is increasing or decreasing magnetism, there is a tendency to an electric current in a conductor at right angles to it.