Energy and Entropy of a Body. 3 



Far as I am from denying that such developments may be of 

 great use to the theory of heat, I nevertheless do not think that 

 it can be said of an equation so obtained, that it expresses a new 

 general principle wherein mine is included as a special case. In 

 my opinion, developments of this kind are only to be regarded 

 as the more complete working out of algebraic calculations for 

 which the data were already furnished by the preexisting fun- 

 damental equations. 



Bauschinger compares his development with those which I 

 have given in my paper " On the Application of the Principle of 

 the Equivalence of Transformations to Internal Work"*, and 

 contends that I have availed myself of a newly introduced mag- 

 nitude, which I call Disgregation, and of the hypothesis " that 

 the mechanical work which heat is capable of producing through 

 any change of arrangement is proportional to the absolute tem- 

 perature at which that change takes place/' while he has worked 

 out his development on purely mathematical principles without 

 any such help. He here seems to have, overlooked the fact that 

 in this paper I had something quite different in view from what 

 he has treated in his. My object was to determine not only the 



quantitative value, but much more, the physical signification of 

 r*jr\ 



the integral \ -^- ; and as a matter of fact I have established 



"# 



that it may be decomposed into two essentially distinct factors, 

 of which one depends solely on the temperature, and the other 

 solely on the arrangement of the constituents of the body. 



When Bauschinger' s paper appeared, I had recently completed 

 a new paper which has since been published in the ' Quarterly 

 Journal of the Zurich Society of Natural Science ' ( Vierteljahres- 

 chrift d. Zuricher naturforschenden Gesellschaft, vol. x. p. 1), and 

 in PoggendorfPs Annalen (vol. cxxv. p. 353), in which, among 

 other matters, I have discussed the determination of the integral 



j -jp- • I have there, as any one may easily convince himself, 



treated the subject in a more general manner than Bauschinger 

 has done; but nevertheless all the equations which there occur 

 are deduced simply as consequences from the two fundamental 

 equations already named. 



It may perhaps be not without interest if I communicate 

 here a few further developments of the same kind, which may 

 serve to complete what are there given, and which appear to me 

 specially fitted to place in a clear light the connexion between 

 this integral and another important magnitude in the theory 

 of heat. 



* Poggendorif 's Annalen, vol.cxvi. p. I'd ; Abhandlungensammlung, part 1. 

 p. 242. [Phil. Mag. S. 4. vol. xxiv. p. 81.1 



B2 



