THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOUKSTAL OF SCIENCE. 



[FOURTH SERIES.] 



JUNE 1862. 



LIX. On the Conduction of Heat by Gases. By R. Clausitjs*. 



THE 108th volume of Poggendorff's Annalen (p. 153) con- 

 tains a paper by M. Jochmann, in which several objections 

 are urged against the hypothesis that the molecules of gaseous 

 bodies are in a state of constantly changing progressive move- 

 ment. 



Jochmann says in the introduction, that he enters npon the 

 discussion of this subject in answer to a challenge from me. In 

 reply to a letter which he very kindly addressed to me, and 

 wherein he expressed some doubts as to the truth of this hypo- 

 thesis, I certainly did give it as my opinion that, if he believed 

 he had any conclusive arguments to urge against it, he ought to 

 publish them; indeed the subject seems to me one of such im- 

 portance, that it is for the interest of science that it should be 

 discussed from as many different points of view as possible. I 

 have myself stated my views of the molecular condition of solid, 

 liquid, and gaseous bodies, and of the change from one condition 

 to another, only as hypotheses ; and hitherto, in all my researches 

 concerning the mechanical theory of heat, I have therefore care- 

 fully distinguished between such conclusions as rest upon cer- 

 tainly established fundamental principles, and which I regard 

 as not to be overthrown, and those which depend upon the views 

 in question. And with the same feeling I would gladly welcome 

 any really trustworthy decision as to the justness of these views, 

 whichever way it might bef. 



* Translated by G. C. Foster, B.A., from Poggendorffs Annalen, vol. cxv. 

 p. 1 (January 1862). 



f I may be allowed to take this opportunity of making a few remarks, 

 which will be in place here, as to the first starting of this hypothesis con- 

 cerning the molecular condition of gases. 



When I published my views concerning the kind of motion which we call 



Phil. Mag. S. 4. Vol. 23. No. 156. June 186.2. 2 F 



