TEMPERATURE ON THE ELECTRIC CONDUCTING-POWER OE ALLOYS. 197 
Table XXVI. 
Metal. 
Conducting-power at 0°. 
Hard drawn. 
Pressed. 
Annealed. 
100-00 
108-57 
Copper 
99-95 
102-21 
Gold 
7796 
79-33 
Aluminium 
56-06t 
Magnesium 
41-17+ 
Zinc 
29-02 
Cadmium 
23-72 
Palladium 
18-44t 
Platinum 
1803t 
Cobalt 
17-221* 
16-81+ * 
Nickel !!!! ! .! 
13-11+ * 
Tin 
12-36 
Thallium 
976 
Lead 
8-23 
Arsenic 
476 
Antimony 
4-62 
Bismuth 
1245 
Gold-silver alloy 
1503 
IV. Miscellaneous and general remarks. 
Having thus described the results obtained in this investigation, it only remains for 
us to make a few general remarks on them. 
1. The percentage decrement in the conducting-power of alloys between 0° and 100° 
is never greater than that of the pure metals composing them; for on looking at 
Tables XI., XII., and XIII., we only find a few cases where the observed percentage 
decrement is greater than that of the pure metals composing the alloy, and in these the 
differences are so small that they are undoubtedly due to small errors in the observa- 
tions, for the differences between the percentage decrements are not greater than those 
obtained for different wires of the same metal. 
2. The conducting-power of alloys decreases with an increase of temperature. This, 
however, is not strictly true for all alloys, for we already know of some where this is 
not the case, viz. a few of the bismuth alloys. The results of our observations are given 
in the following Table : — 
Table XXVII. 
l. 
+Bi Pb lft0 , containing 2*27 volumes per cent, bismuth. 
Length 243 millims. ; diameter 0-512 millim. 
Conducting- power found before 0 Reduced to 0°. 
heating the wire 7'6 97 at 14-5 8-090 
Ditto, after being kept at 100° 
for 1 day 7715 at 14-1 8-099 
T. 
Conducting-power. 
150 
7-693 
57-5 
6-675 
100-0 
5-860 
\=8-101— 0-02802 W+0-00005619!! 2 . 
The conducting-power found in 0 Reduced to 0°. 
a former research \ was 7 - 03 at 24-0 7-633 
* Philosophical Transactions, 1863. 
t Ibid. 1860, p. 161. 
2 . 
fBiPb 10 , containing 18*85 volumes per cent, bismuth. 
Length 122-5 millims. ; diameter 0-673 millim. 
Conducting-power found before 0 Reduced to 0°* 
heating the wire 4-4167 at 15-6 4-5799 
Ditto, after being kept at 100° 
for 1 day 4-4479 at 10-6 4-5586 
Ditto, for 2 days 4-4378 at 11 -5 4-5577 
Ditto, for 3 days 4-4285 at 12-5 4-5587 
T. 
Conducting-power. 
Difference. 
Observed. 
Calculated. 
12-97 
4-4240 
4-4226 
+00014 
24-57 
4-3042 
4-3064 
-0-0022 
37-95 
41769 
47776 
-00007 
54-40 
4-0278 
4-0268 
+00010 
69-48 
3-8973 
3-8961 
+00012 
82-88 
37864 
3-7859 
+0-0005 
94-43 
3-6942 
3-6954 
-0-0012 
X=4-5576— 0-010607 1-\- 0-0000 1 563t 2 . 
The conducting-power found in a 0 Reduced to 0°. 
former research was 4-35 at 20-9 4-565 
