408 Proceedings of Royal Society of Edinburgh. [july 18, 
silver, much confidence cannot be placed upon the resistance 
measurements (in Table XXIII.) ; the changes were so small that, 
with the ordinary form of Wheatstone’s bridge used, sufficient accu- 
racy could not be obtained. 
Table XVII. — Change of Joule Effect in Cadmium. 
Temperature 18° C. to 
Whole per cent, 
increase. 
Mean increase per cent, 
per 1° C. 
110° -8 
32-9 
•354 
122° -2 
32-53 
•315 
143°*8 
38-25 
•304 
173° -0 
3776 
•218 
Table XVIII. — Change of Resistance of Iron. 
Temperature. 
Whole per cent. Increase. 
Mean Increase per cent, 
per 1° C. 
14° -4 C. 
0 
0 
97° -2 
45-4 
•548 
122°-0 
59-9 
•556 
150° "4 
77 7 
•5714 
l78°-9 
95-1 
•5781 
. 197°-8 
109-9 
•5994 
215°-5 
123-7 
•6151 
27 7° -8 
178-9 
•6790 
Table XIX. — Joule Effect in Iron. 
Temperature 18° C. to 
Whole per cent. 
Increase. 
Mean Increase per 
cent, per 1° C. 
Same corrected.* 
110° ’8 
3612 
•389 
•391 
122° -2 
38-4 
*369 
•386 
143°-8 
45-53 
•362 
•380 
l73°-0 
89-13 
•347 
•365 
Table XX. — Change of Resistance of Nickel. 
Temperature. 
Whole per cent. 
Increase. 
Mean Increase 
per cent, per 1°C. 
Temperature. 
Whole per 
cent, in- 
crease. 
Mean In- 
crease per 
cent, per 1° C. 
13°‘0 C. 
0 
0 
239° -3 
115-0 
•5084 
86°T 
29-39 
•4021 
236°-8 
112-4 
•5023 
98°-3 
34-03 
•3990 
271° '7 
139-1 
•5376 
1 49° *7 
57-15 
•4180 
285° -8 
149T 
•5466 
154°-3 
62-84 
•4448 
289°T 
151-6 
•5491 
154°-6 
63T6 
•4454 
290°-9 
152-4 
•5483 
199° T 
88-39 
•4750 
297° T 
159-2 
•5604 
200° -4 
89-78 
•4792 
307°-2 
168-0 
•5711 
210°-4 
94-23 
•4823 
308° -5 
169-4 
•5735 
* For change in resistance of thermopile. 
