TEMPERATURE ON THE ELECTRIC CONDUCTING-POWER OF ALLOYS. 191 
Table XX. 
Alloy. 
Volumes 
Conducting-power at 100°. 
per cent. 
Observed. 
Calculated. 
Tin-copper (hard drawn) 
1-41 of Sn 
48-89 
69-78 1 
Pure copper conducts at 100° 70-27. 
Zinc-copper (hard drawn) 
5-03 of Zn 
47-93 
68-13 J 
Gold-copper (hard drawn) 
1-37 of Cu 
43-85 
55-33 J 
Pure gold conducts at 100° 55-90. 
Pure copper conducts at 100° 70-27. 
Pure silver conducts at 100° 71 "53. 
Pure copper conducts at 100° 70-27. 
Gold-copper (hard drawn) 
0-71 of Au 
62-25 
70-54 
Platinum-silver (hard drawn) . . . 
Copper-silver (hard drawn) 
2-51 ofPt 
1-65 of Ag 
2807 
65-81 
69- 24 
70- 66 
If now, as in the case of most commercial metals, the amount of impurity be much 
smaller than that in the Table, then of course its influence on the value A', 00 is so small 
that it may be entirely disregarded. 
In Tables XXI., XXII., and XXIII., we give some results obtained with impure 
metals, the conducting-power of the same metal in a pure state having been previously 
determined. 
Table XXI. 
1. 
Gold, containing traces of silver (hard drawn). 
Length 1564 millims. ; diameter 0-525 millim. 
Conducting-power found before 0 Reduced to 0°. 
heating the wire 69-612 at 10-2 72-056 
Ditto, after being kept at 100° 
for 1 day 70-069 at 10-4 72-578 
Ditto, for 2 days 69-274 at 13-8 72-578 
T. 
Conducting-power. 
15-0 
68-969 
57-5 
60-179 
100-0 
53-387 
\=72-54S— 0-24692<-f 0-000553U 2 . 
Copper, containing traces of tin (hard drawn). 
Length 2008 millims. ; 
Conducting-power found before 
heating the wire 
Ditto, after being kept at 100° 
for 1 day 
Ditto, for 2 days 
diameter 0-518 millim. 
Reduced to 0°. 
88-357 at 12-8 92-503 
88- 690 at 12-6 92-786 
89- 589 at 10-1 92-894 
T. 
Conducting-power. 
11-0 
89-319 
55-5 
76-619 
100-0 
66-863 
\=92-912 — 0-33482*f+0-0007433*‘ 2 . 
Table XXI. (continued). 
3. 
Copper, containing traces of zinc (hard drawn). 
Length 1992 millims. ; diameter 0-577 m illim . 
Conducting-power found before 0 Reduced to 0°, 
heating the wire 81-306 at 18-2 86-490 
Ditto, after being kept at 100° 
for 1 day 83-185 at 12-8 86-896 
Ditto, for 2 days 83-021 at 12-8 86-725 
T. 
Conducting-power. 
13-0 
82-960 
56-5 
72071 
100-0 
. 
63-786 
\=86-719-0-29814if+0-000688l!! 2 . 
4. 
Copper, commercial, containing traces of iron, nickel, 
lead, and suboxide of copper (hard drawn). 
Length 2091 millims. ; diameter 0-546 millim. 
Reduced to 0°. 
78023 
Conducting-power found before „ 
heating the wire 74-209 at 16-6 
Ditto, after being kept at 100° 
for 1 day 74-610 at 16-2 
Ditto, for 2 days 74-563 at 16-8 
Ditto, for 3 days 74-283 at 18-0 
78-350 
78-441 
78-427 
T. 
Conducting-power. 
12-0 
75-668 
56-0 
66-584 
1000 
59-351 
\ = 78-467 -0-23896if+0-0004780i; 2 . 
2 D 
MDCCCLXIV, 
