Electrical Resistivity of Electrolytic Bismuth. 427 



The bismuth employed was electrolytic bismuth pressed into wire 

 0*5245 mm. in diameter, and its purity was confirmed by spectro- 

 scopic examination. 



These arrangements being made, the observations consisted in 

 measuring the electrical resistance of the bismuth at one tempera- 

 ture, 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 transverse fields employed. 



As the specimens of the bismuth wire used in the various experi- 

 ments 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. 



Hartman and Brauns Pure Electrolytic Bismuth. 



Resistivity of Bismuth Transversely Magnetised at Ordinary Tem- 

 peratures ( + 19C.). 



Strength of field Yolume resistivity in 



(C.a.S. units). C.GLS. units. 



116,200 



1,375 118,200 



2,750 123,000 



8,800 149,200 



14,150 186,200 



21,800 257,000 



Resistivity of Bismuth Transversely Magnetised at 79 C. 



Strength of field Yolume resistivity in 



(C.G.S. units). C.G-.S. units. 



78,300 



650 83,300 



2,300 103,500 



3,350 114,800 



4,100 134,000 



5,500 158,000 



7,900 201,000 



14,200 284,000 



