ON THE DISSIPATION OF ENERGY. 457 



by the political miscarriages of his country and 

 repetitions of revolutionary violence, we should 

 have learned much more from him. Manuscript 

 journals and memorandums, found among his 

 papers and published l after his death (but not 

 published before Joule had finally convinced the 

 world of the immateriality of heat and had 

 measured its dynamical equivalent), proved that 

 Carnot had lived long enough to see irrefragable 

 reasons for abandoning the doctrine of the 

 materiality of heat and for confidently believing 

 that heat is in reality motion among the particles 

 or molecules or atoms of matter ; and that he had 

 taught himself decisively and thoroughly the 

 doctrine of the " Conservation of Energy," which 

 ten years later was given to the world by Joule 



1 " Reflexions snr la Puissance Motrice du Feu et snr les Machines 

 propre a Developper cette Puissance, par S. Carnot, ancien Eleve de 

 VEcole Polytechniqtte, Paris, 1878. Of this publication, with its 

 appendices of biographical sketch by his younger brother Hippolyte 

 Carnot, and extracts from unpublished writings of Sadi, an English 

 version has been published in America (and in England, Macmillan 

 & Co., 1890) under the editorship of Dr. Thurston, Cornell 

 University, who adds to it a short article by himself, on "The 

 Work of Sadi Carnot," full of interesting matter. 



