Forces of some Metallic Alloys in Contact with Copper. 43 



later, 292*63 ; and six days after casting, 274*12. These expe- 

 riments show distinctly that the thermoelectric force (and conse- 

 quently also the electromotive force) of this alloy diminishes with 

 time. 



Copper and Alloy No. 5. 



The constituents were 32 parts bismuth and 1 part antimony. 

 The electromotive force. — 



Experiment 36. 

 5= tan 19° 20'. 



Experiment 37. 

 s= tan 12° 45'. 



Experiment 38. 

 s= tan 7° 0'. 



Deflections. 



Deflections. 



Deflections. 



86-48 

 88-15 



57-60 

 57-55 

 58-00 



360 

 35-9 

 34-2 



Mean... 87'32 



5772 



35-37 



This gives ft = 4*213 and 



a = 306*70 with s=tan 19 20 



« = 281*25 

 a = 297*08 



s=tan 12 45 

 5= tan 7 



Mean . « = 295*01 

 In the first determination there was obtained {3= 6*083 and 



o, = 307-61 with 5 = tan 16 14 

 a = 290*19 „ 5 = tan 8 35 

 u = 298*64 „ 5 = tan 4 6 



Mean . « = 298*81 

 The two values of a do not differ much from each other. 

 The thermoelectric force : — 



Experiment 39. — No. 1. 



Temperature- 

 differences. 



Deflections. 



Conducting-power. 



o 



10-5 

 10-3 

 10-2 

 100 



217*8 

 214-8 

 213-8 

 210-8 



163-6 

 112-8 

 113-4 



Mean... 10-25 



214-3 



113 3 



The deflection, reduced, becomes 295*24. 



The experiment with the pair of wires No. 2 could not be 

 carried out, because in the preparation of the experiment it was 

 injured at the joint. In the first determination values of the 

 thermoelectric force but little differing were obtained for the two 



