390 Proceedings of Royal Society of Edinburgh. [july 18, 
Table I. 
Temperature C. 
Mean 
Thermopile 
Deflection. 
Mean Current 
Deflection. 
Observed 
Ratio of 
Peltier 
Effects. 
Ratio of 
Currents. 
18° 7 to 1 8°*9 
19°-1 to 19°'3 
265-9 
129-7 
798 
398 
2-044 
2-005 
95° -5 to 95° *9 
121-6 
877-9 
2-143 
2-106 
95° -9 to 96° *2 
52-25 
415*9 
95° 7 to 96°'2 
72-17 
718-1 
1-899 
1-910 
96°-2 to 96°-7 
36-13 
375-9 
20° -7 to 21° -3 
174-0 
206-7 
1-796 
1 -772 
21°*3 to 21°'3 
97-9 
116-7 
The following are some of the measurements at different tempera- 
tures 
Iron and Cadmium. 
Iron and cadmium were selected as having a comparatively low 
neutral point. The specimens used were ordinary sheet iron and 
tolerably pure cadmium. The neutral point found by heating up 
a junction in oil was 144° ’0 C. At 144° C. the direct measurement 
showed absolutely no Peltier effect , a small irreversible effect alone 
being visible ; while the same current gave a mean deflection of 
308 scale divisions at 21° C, and -240 divisions at 199°T C. 
Also at 139°’0 the Peltier effect was small, but still of the same 
sign as that at 21° C. Table II. gives some measurements at other 
temperatures, the last column being the ratio of the Peltier effects 
Table II. 
No. 
Low Tempera- 
ture. 
High Temperature. 
Observed Ratio. 
Calculated Ratio. 
1 
0° 
o 
2 
66° -9 
1-475 
1-447 
2 
O 
o 
!>> 
rH 
72° -6 
1-782 
1-878 
3 
f— 1 
OO 
0 
OO 
95°-7 
2-073 
2-050 
4 
19°-2 
95°-l 
2 051 
2-024 
5 
17° "8 
199°-1 
-1-271 
-1-410 
