428 



Profs. J. Dewar and J. A. Fleming. On the 



Resistivity of Bismuth Transversely Magnetised at 185 C. 



Strength of field 

 (C.G.S. units). 







1,375 



2,750 



8,800 



14,150 



21.800 



Yolunie resistiyity in 

 C.GKS. units. 



41,000 



103,300 



191,500 



738,000 



1,730,000 



6,190,000 



Hartman and Braun's Pure Electrolytic Bismuth. 

 Resistivity of Bismuth Transversely Magnetised at 203 C. 



Strength of field 

 (C.G-.S. units). 





 2,450 



Volume resistivity in 

 C.G-.S. units. 



34,300 

 283,500 



Electrical Resistivity of Bismuth in C.G.S. units, transversely 

 magnetised in a Constant Magnetic Field, but at variable Tem- 

 peratures. 



It will be seen that the observations lead to the following conclu- 

 sions. If the transverse field is zero, then cooling the bismuth always 

 reduces its resistance. If then the bismuth is transversely magnetised, 

 the resistance is increased, and for every temperature below the 

 normal one (about 20 C.), there is some particular strength of trans- 

 verse field, which just annuls the effect of the cooling, and brings the 

 resistance of the bismuth back again to the same value it had when 

 not cooled, and not in any magnetic field. Hence the curves showing 

 the resistance at any temperature lower than the normal one (20 C.) 

 as a function of the transverse field, cross the curve showing the 

 resistance as a function of the field when taken at the normal tem- 

 perature. These crossing points are, however, not identical for 



