512 Laws regarding Direction of Thermo-electric Currents. 



of the metal, shows perhaps more clearly than the table the 

 want of agreement of the theory with fact. On the theory 

 the current flows from hot to cold in that metal of a pair 

 whose abscissa is the greater. According to the observations 



Abscissa : 

 Quotients of Conductivities. 



Ordinates : 

 Thermo-electric Powers. 



the current flows from hot to cold in that metal of a pair 

 whose ordinate is the greater. The two are only in agree- 

 ment when the line on the diagram joining the two points 

 corresponding to any two metals slopes upward to the right. 

 It is obvious that the number of exceptions to this rule, even 

 for the metals dealt with, must be almost as large as the 

 number of agreements, and that the laws enunciated by 

 M. Thomas are not supported by the observed facts. 



