﻿Fields on the Electric Conductivity of Bismuth, ili.j 



Table II. 



Magnetic Field. 

 O.G.S. 



Resistance. 

 Ohms. 



Resistance with 



that in zero-field 



as unity. 



Percentage- Increase 



of Resistance for 



comparison with 



Table I. 







8-57 



1-0 







5830 



1054 



1-227 



22-7 



(5310 



10-74 



1-253 



25-3 



6830 



1104 



1-290 



29*0 



7790 



1147 



1-341 



341 



8880 



12-06 



1-407 



407 



10410 



12-83 



1-496 



49 6 



12500 



13-97 



1-630 



630 



15710 



1500 



1-830 





20450 



18-57 



2-160 





23480 



2002 



2-333 





26820 



2150 



2-508 





27450 



21-76 



2540 





27820 



2207 



2-568 





28370 



22-37 



2-609 





29270 



2265 



2-643 





3001)0 



23-20 



2-704 





31270 



23-77 



2-772 





32730 



24-40 



2-846 





32820 



2432 



2-837 





33300 



24-78 



2-893 





35800 



16-29 



3O70 





36600 



27 03 



3160 





38900 



28-56 



3334 







Series at 18° C. 



with small spiral. 





To enable a comparison to be made with the series for the 

 large spiral at 18° C. the percentage increase in fields up to 

 13,000 is also given, and these values are plotted along with 

 those for the large one in fig. 6, the crosses denoting the 

 points got from the small spiral. The diagram shows that 

 the two spirals agree at this temperature. 



PL XV. fig. 7 represents the series given in Table II. in 

 graphic form. It will be seen that the resistance is more than 

 tripled in the highest field at 18° ; and for a lower temperature 

 it would have a still higher value, and, vice versa, for a higher 

 temperature, a lower. 



The four highest fields in the above series were obtained by 

 means of the ring-magnet, and as the apparatus was arranged 

 specially to suit the Ruhmkorff', the same exactitude does not 

 apply to these readings as to the others. The magnet had a 

 very large influence on the galvanometer, which was elimi- 

 nated by repeating each experiment with the current reversed 



