﻿on the Contact of different Metals, 25 



Deflections. 

 13-2 

 10-2 



9-7 



9-7 

 11-0 

 10-2 

 10-2 



Mean . . 10-6 

 Intensity of current = tg. 34° 15'. 

 Therefore, with an intensity = tg. 45°, the deflection becomes 

 equal to 15-57. 



Experiment 11. — In this experiment the copper wire was sol- 

 dered by means of tin to a bismuth rod 2*5 millims. square. 

 When at the place of contact the positive current went from 

 the bismuth to the copper, cooling resulted. 



Deflections. 

 103-5 

 107-5 



Mean . . 105-5 



Intensity of the current = tg. 36° 45'. 



With an intensity = tg. 45° the deflection becomes equal to 

 141-3. 



Experiment 12. — The copper wire was soldered to a silver 

 wire 0*6 millim. in diameter. With this combination not the 

 least deflection could be observed. The same was the case with 

 a combination of zinc and copper. 



The foregoing experiments give the following electromotor- 

 series, in which, when two successive metals are in contact, the 

 current at the place of contact goes from the preceding to the 

 succeeding — bismuth, argentan (German silver), platinum, cop- 

 per, and iron. The two metals silver and zinc are so near copper 

 that the experiments left it undecided whether they precede or 

 succeed the last-named metal. The relative numerical values 

 are as follows : — 



Bismuth-copper . . . 141*3 

 Argentan-copper . . . 15-57 

 Platinum-copper . . . 7*37 

 Copper-iron .... 17*83 

 5. In order to ascertain the thermoelectric relations of these 

 metallic combinations, the following experiments were made. 

 The soldered wires were twice bent near the soldering, so that 

 they were parallel to each other, and the place of contact was 

 inserted in a test-tube which was placed in a large vessel filled 



