102 PROCEEDINGS OF THE AMERICAN ACADEMY. 



(1) (2) (3) (4) (5) 



180 X 10- 6 300 X 10- 8 8 X 10- 4 300 X 10" 7 -10 X 10" 4 



The negative sign of the value of (5) indicates, as Bams points out, 

 that in liquid mercury " the immediate electrical effect of rise of tem- 

 perature, ... .is a decrement of specific resistance." 



Whether a like statement would hold true of other metals in the 

 liquid state we have, so far as I am aware, insufficient data to deter- 

 mine. 



Summary. 



1. It is pointed out that thermal capacity of the electrons seems 

 to be a necessary condition for thermoelectric action. 



2. It is assumed that, through a considerable range of temperature, 

 the number of free electrons per cu. cm. of a metal is represented by 

 the formula n = k n T", where k n and v are constants, T being absolute 

 temperature, and that R, of the equation pv = RT, "reckoned for a 

 single electron," is represented by the formula R = k r T p , where k r and 

 p are constants, R being less, at ordinary temperatures, for an electron 

 than for a gas molecule. 



3. Electric conduction is supposed to be maintained in part by 

 free electrons, (B), acting very much like gas molecules in the intera- 

 tomic spaces of the metal, and hi part by other electrons, (A), which 

 pass directly from atom to atom, perhaps during collisions, without 

 taking part in the gas-pressure action of the (B) electrons. 



4. Formulas are obtained for the specific conductivity and the 

 Thomson effect coefficient of a metal, as these properties would be if 

 dependent entirely on the free electrons; and it is found that these 

 two expressions are either incompatible with each other or in disac- 

 cord with observed facts. Argument leads to the conclusion that the 

 free electrons are necessary for the phenomena of thermo-electric 

 action but play an unimportant part in electric conduction. 



5. Expressions are found for the Peltier effect and for the difference 

 of "virtual" potential at the junction of two metals, virtual potential 

 being due in part to electric charge and in part to the specific attraction 

 of metals for the electrons. In this connection the Volta effect is 

 discussed. 



6. Inspection of the formula obtained for the net e.m.f. of a thermo- 

 electric circuit shows this total to be dependent on the 7"s, n's, e's and 

 p's of the system and not upon any specific attraction of metals for 

 the electrons. 



