154 
PHYSICS: E. H. HALL 
Proc. N. a. 
suits comes from the substitution of one hypothesis for the other. Hy- 
pothesis (B) seems to give, other things being equal, somewhat larger 
values of do than hypothesis (A). 
TABLE 18: COBALT. 
K = 7.8, ^2 = 0, C2 = 0 
C, or 
ikf-^k), 
at 0° 
Ci = 202 X 10-6 
Ci = 230 X 10-6 
Ci = 260 X 10-6 
Ci = 303 X 10-6 
Q 
0 
0 
0 
So 
(kf ^ k) 
at 100° 
Q 
(kf ^ k) 
at 100° 
Q 
{kf ^ k) 
at 100° 
Q 
(kf H- k) 
at 100° 
0.01 
0.05 
0.10 
.038 
.004 
.030 
.070 
0.5 
0.5 
0.5 
.029 
.007 
.033 
.073 
.020 
.007 
.036 
.076 
1.5 
1.5 
1.5 
.010 
.005 
.040 
.080 
C, or 
Ci = 455 X 10-6 
Ci = 607 X 10-6 
ikf-i-k); 
at 0° 
Q 
So 
(kf ^ k) 
at 100° 
Q 
(kf-^k) 
at 100° 
0.10 
2.5 
3 
0.15 
2.5 
0.002 
0.196 
3 
0.20 
2.5 
0.007 
0.246 
3 
0.005 
0.261 
0.30 
2.5 
0.016 
0.346 
3 
0.019 
0.361 
0.40 
2.5 
0.026 
0.446 
3 
0.032 
0.461 
TABLE 19: BISMUTH. 
Ki = —3.2, = 0, C2 = 0 
C, or 
at Oo 
Ci 
= —83 X 10-6 
Ci 
= —93 X 10-6 
Ci = —106 X 10-6 
Q 
{kf-^k) 
at 100° 
Q 
(kf-^k) 
at 100° 
Q 
ikf-^k) 
at 100° 
0.01 
0 
0.07 
0.002 
0.5 
0.05 
0.001 
1.5 
0.03 
0.000 
0.10 
0 
0.25 
0.092 
0.5 
0.17 
0.091 
1.5 
0.10 
0.089 
0.20 
0 
0.46 
0.192 
0.5 
0.32 
0.191 
1.5 
0.18 
0.189 
0.40 
0 
0.87 
0.392 
0.5 
0.58 
0.391 
1.5 
0.34 
0.389 
0.60 
0 
1.28 
0.592 
0.5 
0.84 
0.591 
1.5 
0.50 
0.589 
In a paper already well advanced I shall undertake to show how far 
the data obtained in the present paper enable us to go in the way of ex- 
plaining thermal conduction in the metals here dealt with. 
^ Eq. (7) is obtained from eq. (1) of my paper in the Proceedings of the National 
Academy of Sciences for April, 1918, by substituting for from eq. (2) of that paper 
(which equation should have n instead of m) and then making obvious changes. 
2 Proceedings of the Amer. Acad, of Sciences, Vol. 53, No. 4, 1918, pp. 269-386. 
These values are not regarded by Bridgman as accurate, having been obtained as second 
derivatives of e. m. f. values, the quantities measured; but taken as a whole they seem 
to be the best available data for the present purpose. 
^ This assumes that X'o is constant. 
^ When (kf-T-k) is infinite, we have the conditions discussed in my paper "Thermo- 
electric Diagrams on the P-V Plane," Proc. Amer. Acad., Boston, February, 1918. 
