Wiedemann and Franz on the Conductibility of Metals for Heat. 39 



rical comparison may be desirable, we here present it to the 

 reader. In the following table the conductivity of silver is as- 

 sumed to be 100, and certain trifling corrections are introduced 

 for the purpose of translating the indications of the galvano- 

 meter into those of the ordinary thermometer : — 



Twenty years ago Professor Forbes was led to suspect that 

 those metals which conducted heat most perfectly were also the 

 best conductors of electricity*. We here transcribe a table, 

 comparing the results arrived at by Wiedemann and Franz on 

 heat, with those obtained by Riess, Becquerel and Lenz, upon 

 electricity. 



Whatever the quality may be upon which calorific conduction 

 depends, the above table renders it exceedingly ])robable that 

 the same quality influences in a similar manner the transmission 

 of electricity ; for the divergences of the numbers expressing 

 the conductivity for heat from those cxpi'cssing the conductivity 

 for electricity arc not greater than the divergences of the latter 

 alone, exhibited by the results of the difi"crent observers. 

 * Phil. Mag. .S, 3. vol. iv. p. 27. 



