Forces of some Metallic Alloys in Contact with Copper. 39 



The deflections, reduced, are : — 



For No. 1, =13411 

 " No. 2, =157-38 



Mean . . =14575 

 From the first determination of the electromotive force, made 

 immediately after the casting, I obtained /3 = 4*008 and 



a=184-8with s=tan26 34 

 « = 162-7 ;, s=tanl6 3 

 a = 176-4 „ 5= tan 6 37 



Mean . . a= 174-63 



Hence the electromotive force directly after the casting was 

 sensibly greater than in the later experiments. About ten days 

 after the casting the reduced deflections of the thermoelectric 

 current were : — 



For No. 1, =134-91 

 „ No. 2, =165-83 



Mean . . =150*37 

 This value is but little greater than that obtained in the later 

 experiments. Probably the molecular change which brought 

 about the diminution of the electromotive and thermoelectric 

 forces had for the most part already commenced when the first 

 thermoelectric experiments were made. 



Alloy No. 3 and Copper. 

 The constituents of this alloy were 2 parts bismuth and 1 

 part tin. 



The electromotive force. — 



Experiment 21. 

 5= tan 19° 12'. 



Experiment 22. 

 s=tanl3° 23'. 



Experiment 23. 

 s= tan 7° 40'. 



Deflections. 



Deflections. 



Deflections. 



1200 

 13-85 

 13-65 

 12-35 



8-70 

 8-90 

 9-65 



6-00 

 6-75 

 6-20 



Mean... 12-96 



9-08 



6-32 



We obtain /3= 8-275 and 



a = 52-68 from Exp. 21. 

 a = 46-25 „ 22. 



*= 50-35 „ 23. 



Mean . . a =49-76 



