3Ö0 



\Vè can have. It has ah-eady been found that the conductivity of heat 

 and electricity is a periodic function of the atomic weights of elements 

 and now it is seen that the leinpeiatiire coefficient of electric con- 

 ductivity of metals is also a periodic function of the atomic weights 

 and as the two properties, as has been already observed, are very 

 much related, it seems very probable that the temperature coefficient 

 of the conducti\^ity of heat of elements would also be a periodic 

 function of their atomic weights. 



Torsional rujidiUj, Young's nuxlulun and their temperature coef- 

 ficients. 



The following table is obtained from Lanuolt und Börnstkin's 



Tabellen. E represents the Young's modulus, A^ its temperature 

 coefficient. T indicates the values of torsional rigidity and L^ its 

 tenii)crature coefficient. 



