64 
PHYSICS: E. H. HALL 
Proc. N. A. S. 
this formuJa, with the tentative values of (k f -5- k) and X obtained for 
each metal in my paper on the Thomson Effect and Thermal Conduction, 1 
agree with those found by Bridgman from his experiments. Close agree- 
ment is, of course, not to be expected, even if my theory is everywhere 
correct, for the values of (kf -5- k) and X given in the paper just mentioned 
were obtained without any regard whatever for the Peltier effect, they 
being merely certain values, not the only values, that will, approximately 
at least, meet the requirements of the Thomson effect and thermal con- 
ductivity. Moreover, the experimental data used in arriving at these 
values are doubtless faulty in many particulars; for example, in a number 
of cases I had no observed value of the thermal conductivity at 100° C, 
and was obliged to make use of a value calculated, not very safely, by 
means of the Wiedemann-Franz law. 
Departing from the common practice, I have substituted bismuth for 
lead as the reference metal, taking as mv definition of the Peltier heat the 
amount of heat (ergs) absorbed in tl jfc assage of (1 -f- e) electrons from 
any given metal to bismuth. All the values in the table below are to be 
multiplied by 10 4 . Con. is constantan and Man. is manzanin. 
table i 
The Peltier Heat 
OF VARIOUS METALS AGAINST BISMUTH 
At 0° C. 
At 100° c. 
I 
II 
in 
IV 
V 
VI 
VII 
VIII 
IX 
Obs. 
Calc. 1 
Calc. 2 
Calc. 3 
Obs. 
Calc. 1 
Calc. 2 
Calc. 3 
V-VIII 
Fe 
247 
798 
311 
251 
310 
861 
323 
226 
84 
Mo 
219 
814 
327 
217 
319 
911 
373 
252 
67 
Zn 
211 
822 
335 
212 
274 
904 
366 
225 
49 
Au 
211 
804 
317 
210 
280 
888 
350 
227 
53 
Cu 
211 
817 
330 
211 
280 
905 
367 
229 
51 
Ag 
210 
831 
344 
209 
279 
925 
387 
226 
53 
Tl 
208 
778 
291 
209 
271 
850 
312 
221 
50 
W 
207 
748 
261 
208 
285 
822 
284 
234 
51 
Sn 
204 
799 
312 
204 
266 
880 
342 
220 
46 
Mg 
203 
769 
282 
202 
266 
846 
308 
220 
46 
Al 
202 
772 
285 
201 
263 
844 
306 
210 
53 
Pt 
195 
783 
296 
194 
245 
847 
309 
195 
50 
Pd 
188 
747 
260 
188 
232 
795 
257 
182 
50 
Co 
156 
645 
158 
154 
172 
642 
104 
117 
55 
Ni 
155 
650 
163 
153 
187 
668 
130 
136 
51 
Bi 
0 
0 
0 
0 
0 
0 
0 
0 
0 
Con. 
108 
533 
36 
108 
106 
493 
—45 
55 
51 
Man. 
207 
591 
104 
206 
275 
604 
66 
223 
52 
Column I gives the observed, or experimentally found, values of II, 
with respect to bismuth, at 0° C. Column II gives the values calculated, 
