Page:Proceedings of the Royal Society of London Vol 60.djvu/459

Rh The bismuth employed was electrolytic bismuth pressed into wire 0'5245 mm. in diameter, and its purity was confirmed by spectro

These arrangements being made, the observations consisted in measuring the electrical resistance of the bismuth at one temperature, but when the transverse magnetic field had values varying from zero to nearly 22,000 C.G.S. units.

In the following tables the results are collected. The electrical resistivity of the bismuth is stated for each temperature, and for the various Gansverse fields employed.

As the specimens of the bismuth wire used in the various experiments had different lengths, the actual figures of observation are not given, but they have been reduced so as to give the volume resistivity of the bismuth, corresponding to a certain temperature and magnetic field strength.

In the case of the experiment in liquid air boiling under a reduced pressure, on account of the size of the vacuum vessel necessary to contain the required initial volume of liquid air, the pole pieces of the magnets could not be brought very near together, and hence the field could not be raised to a very high value.

Resistivity of Bismuth Transversely Magnetised at Ordinary Temperatures ( -f 19° C.). scopic examination.

Hartman and Braun sPure Electrolytic Bismuth. Strength of field (C.G.S. units).

Volume resistivity in C.Gr.S. units. 116,200 118,200 123.000 149.200 186.200 257.000 1,375 2,750 8,800 14,150 21,800

Resistivity of Bismuth Transversely Magnetised at —79° C. Strength of field (C.G.S. units!. 0 650 2,300 3,350 4,100 5,500 7,900 14,200

Volume resistivity in C.G.S. units. 78.300 83.300 103,500 114,800 134.000 158.000 201.000 284,000