1 \'2 The Influence of Stress and Strain on Matter. [June 19, 



where T is the melting point temperature reckoned from absolute 

 zero, ft the coefficient of linear expansion, and proportional to the 

 distance between the centres of adjacent molecules. From the 

 above relation combined with those already mentioned we deduce 



- p=a constant ; 



and - "=a constant. 



ej 



The first of these two relations was found to hold good for ten out 

 of twelve metals examined, but for the metals bismuth and antimony 

 the ratio T/3 : CJ is almost exactly one half of the ratio obtained for 

 the other metals. It was concluded that for most metals the melting 

 point temperature may be approximately calculated from the 

 formula 



T= -02253 X^-. 

 ft 



Where C r and ft represent the mean thermal capacity per unit volume, 

 and coefficient of expansion respectively between C. and 100 C. 



The second of the two relations was found also to approximately 

 hold good. 



Altogether the following relations have been approximately 

 established by experiment : 



(1) ^L_=a constant, 



6ml 



or more probably -^= a constant; 



(2) -= a constant, 



(3) .-cL= a constant, 



6T 



or more probably 1_= a constant. 



ej 



In these relations we may substitute for C r , where A is the 



A 



density and A the atomic mass. 



In the paper will be found a full discussion of the experiments of 

 Joule* and Edlnndf on the thermal effects produced by mechanical 

 stress in metal?. 



* " Phil. Trans.," 1859, vol. 149, p. 91. 



t " Ann. de Phjs. und Chemie," Band cxxvi, p. 539. 



