TE3IPEEATUEE ON THE ELECTEIC CONDUCTING- POWEE OF METALS. 13 
T. 
Conducting power. 
Difference. 
! 
T. 
Conducting power. 
Difference. 
T. 
Conducting power. 
Difference. 
Observed. 
Calculated. 
Observed. 
Calculated. 
Observed. 
Calculated. 
li*60 
24*24 
41*33 
55*08 
70*27 
82*01 
98-07 
27*915 
26-639 
25-077 
23-925 
22-757 
21-924 
20-865 
27-902 
26-653 
25-086 
23-926 
22-747 
21-912 
20-875 
+ 0-013 
—0-014 
— 0-009 
-0-001 
+ 0-010 
+ 0-012 
-0-010 
11-20 
26-12 
39-55 
54-18 
72*32 
85-77 
100-23 
27*706 
26-187 
24-951 
23-719 
22-330 
21-407 
20-540 
27-687 
26-199 
24-959 
23-716 
22-330 
21-414 
20-534 
+ 0-019 
-0-012 
-0-008 
+ 0-003 
0-000 
-0-007 
+ 0-006 
11*16 
25*96 
40*10 
56-85 
71*73 
85-40 
98-95 
27*518 
26-088 
24-812 
23-423 
22-306 
21-348 
20-462 
27-613 
26-090 
24*820 
23-428 
22-295 
21-339 
20-472 
+ 0-005 
-0-002 
— 0-008 
-0*005 
+ 0-011 
+ 0*009 
-0-010 
The formulae deduced from the observations, from which the conducting powers were 
calculated, were — 
For first wii'e . . X=29-114-0-10727?^+0-0002372f. 
For second wire . X=28‘881— 0T0949^-{-0-0002616^^ 
For third wire . . X=28•649-0•10424if+0•0002182^^ 
No permanent alteration in the conducting power takes place after heating the wires 
for several days to 100°. 
The value formerly found for the conducting power of zinc (precipitated galvanoplas- 
tically, fused and pressed) was — 
o Eeduced to 0°. 
27-39 at 17-6 29-220. 
Treating these values as before, we find the formula for zinc to be 
X=29-022-0-10752^+0-0002401f. 
Cadmium. 
The metal was purified as described in the Philosophical Transactions, 1860, p. 177. 
The wires were pressed. Table VI. shows the results. 
Table VI. 
First wire. 
Second wire. 
Third wire. 
Length 
625 millims. 
0*641 millim. 
559 millims. 
0-678 millim. 
439 millims. 
0-684 millim. 
Diameter 
Tlie means of the conducting powers found for each of the following temperatures 
were — 
T. 
Conducting power. 
Difference. 
T. 
Conducting power. 
Difference. 
T. 
Conducting power. 
Difference. 
Observed. 
Calculated. 
Observed. 
Calculated. 
Observed. 
Calculated. 
8*87 
20-75 
34-47 
49-38 
63-39 
77-74 
93*55 
23-327 
22-351 
21-241 
20-138 
19-188 
18-292 
17-325 
23-329 
22-338 
21-255 
20-150 
19-186 
18-268 
17-339 
-0-002 
+ 0-013 
—0-014 
— 0-012 
+ 0-002 
+ 0-024 
-0-014 
8-89 
21-59 
36-37 
48*52 
62-90 
80-00 
23-374 
22-280 
21-075 
20-157 
19-171 
18-109 
23-400 
22-270 
21-059 
20-146 
19-162 
18-131 
-0*026 
+ 0-010 
+ 0-016 
+ 0-011 
+ 0-009 
— 0-022 
14-60 
22-05 
39-65 
54-45 
68-10 
81-20 
89-90 
21-849 
21-318 
20-072 
19*065 
18*179 
17-393 
16-896 
21-8591 
21*310 
20-061 
19-067 
18-194 
17-397 
16-888 
— 0-010 
+ 0-008 
+ 0-011 
—0-002 
-0-015 
— 0-004 
+ 0-008 
