310 Resistance of Bismuth to Alternating Currents. 



The results of these experiments, although they do not 

 indicate what really takes place in the bismuth, show that, 

 whatever it is, it may be represented by an alternating E.M.F. 



Tier. 10. 



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set up in the bismuth, the magnitude and phase of which for 

 frequencies between 10 and 60 per sec. is very nearly given 

 by the equations 



^ sin a= -0035 + '0003 n, 



60 



and 

 so that 

 and 



E 



cos a= -000266 7*, 



tan «= 1*13 + 



13-2 



~ =-0035 + -00039 n. 

 Hi 



On studying Curve I. (fig. 2) it can at once be seen that 

 these conclusions explain the results obtained by M. Sadovsky. 

 For, on closing the galvanometer-arm of a bridge, which has 

 been balanced for steady currents during the 60° of rising 

 current, a current represented by the area ADBC would pass 

 through the galvanometer; this would appear to be due to 

 a rise in the resistance of the bismuth. On closing the 

 galvanometer-arm for the next 60° a current, represented by 

 the area CDE, would pass through the galvanometer ; this 

 current would be less in value, but of the same sign as the 

 previous one : hence, again, the resistance of the bismuth 

 would appear to have been raised. This, then, accounts for 

 the apparent fact that 



