TEMPEEATIJEE ON THE ELECTEIC CONDHCTINa POWEE OF METALS. 27 
The mean of the conducting powers given in the Tables agrees very well with the 
mean of the former determinations made with wires of metals of different preparation to 
that of those used for the experiments described in this paper. 
The following questions have suggested themselves during the foregoing investigation, 
the answers to which we reserve for ourselves. It is intended to make them the sub- 
jects of short communications, which from time to time will be laid before the Eoyal 
Society : — 
1. Will a hard-drawn wire become partially annealed by age 1 and, on the other hand, 
will an annealed wire become partially hard drawn 1 
2. Will bismuth or tellurium return to their original conducting power in time, or by 
exposure to intense cold 1 
3. Whether by heating tellurium or any of the metals to a higher temperature than 
100° we should not arrive at the same result in a much shorter time. 
4. What are the thermo-electric properties of bismuth, antimony, tellurium, &c. after 
being kept at 100° for several days'? will they not have altered'? It is remarkable that 
bismuth, which stands at one end of the thermo-electric series, should gain in conduct- 
ing power after heating for some days, and that antimony and tellurium, at the other 
end of the series, should lose, the one slightly, the other, -with a much higher thermo- 
electric number, to a very great extent. 
5. Will tellurium conduct better in a melted state than the solid? 
6. "VMiat law do the alloys follow as regards the influence of temperature on their 
conducting power ? 
