Page:Proceedings of the Royal Society of London Vol 60.djvu/464

432 a certain temperature at which the bismuth has a minimum electrical resistivity, and, therefore, a zero temperature coefficient, and that the temperature of this turning point is higher the strouger the transverse field. These curves also show that at a temperature of about 150° C., the bismuth would probably cease to have its resistivity affected by a transverse magnetic field.*

In conclusion, we desire to mention the assistance we have received from Mr. J. E. Petavel in the work described above.

field of 7000 C.G-.S. units, the total percentage increase of resistance of electrolytic bismuth was 22'0, 8'0, 1‘0, and 0‘4 per cent, respectively at temperatures of 16° 0., 100° C., 223° C., and 290° C.
 * Drude and Nernsfc Wied. Ann.,’ vol. 42, p. 568) found that, with a transverse