1195 



of kinetic and potential energy in the neutral point M (hence in all 

 the points of the path [)assed over by iM) the quantity ^'^Nin ?/'/_« 

 does not represent the whole spacial Energy E, but only 7» V^^'^ 

 of it. Likewise N^f{l — sf will not represent the whole energy of 

 attraction^) (zero point energy) E^, but again V» ^^V)- Hence we may 

 put: 



Nmx7^nT ; '/^Nmn^' ='/,{E—E^), 



80 that according to (7) we have at high temperature: 



(V'zrroo) RT=iiE-E, ) (8) 



That this equation is correct, appears from this that it gives for c„: 



dE 

 {T.= oo) c, = — = SR=6 



aJ 



in gr. cal., hence the expected double heat capacity, which is only 



= 3 for large volumes (gases) under the same circumstances (i.e. 



high temperatures) — - always on the supposition of mon-atomic 



substances, as otherwise the internal energy of the atoms within 



the molecules will still be added to E. 



We still point out, that when the molecules were perfecthi rigid 



systems, hence could not be pressed in, the quantity e in our formula 



(6) for u^ would be infinitely great, and therefore the duration of 



collision absolutely =: 0, so that then not the first terms with 



I y/m t y/m 



\/ — . (p would be cancelled by the second with \n\/ — , 

 V 2f '^ ■ " IX 2g 



when cp approaches 0, but just the reverse: these latter terms would 

 disappear by the side of the former, however small these might be 

 on account of rp. But accordingly then w' will not become = 7» ^o'» 

 but = u^\ hence R7'= '^1, (E—Eq), so that Cv= would become 

 7, R = 3 and not = 6. That, therefore, the capacity of heat for 

 condensed systems does not approach to 3 but to 6, is a proof that 

 the molecules may not be considered as perfectly rigid spheres, but 

 are elastic systems, liable to compression, in which the time of 



1) We point out that for the limiting volume v = b(l = s) our En = SNf(l — s)^ 

 will approach to 0. In fact, as all movement is then impossible, the energy 

 ^joNmu- can in this case not undergo any increase in consequence of the work 

 of attraction. Of course by the side of the E^ introduced by us, another z.ero point 

 energy may always be introduced, which is in connection with that of the atoms 

 (systems of electrons) within the molecule. The formulae are, however, not 

 modified by this in any respect. 



2) Division by 3 can also be justified by this that for the linear systems 

 considered by us the velocities are all velocities ?/,« directed normally with respect 

 to the molecules. And now u,i^ = Vs **'. 



