Propagation of Heal in Liquids. 289 



brought into contact with its sides by the currents formed in the mass 

 of the liquid, a long time, I say, after I had adopted this opinion, I 

 continued to doubt whether single particles of warm water, when com- 

 pletely surrounded by particles of cold water, and remaining undis- 

 turbed in the midst of them, might not be able to communicate to 

 these neighbouring particles that excess of heat which the shortness of 

 the time of contact when the particles are in motion does not allow 

 them to impart to each other. Indeed, if the property of water by 

 which it is an apparent non-conductor of heat depends solely upon 

 the extreme mobility of its particles, it is evident that the communica- 

 tion of heat, under the circumstances just supposed, must necessarily 

 take place ; and it must be remembered that in this case the fluidity of 

 the liquid, as far as the particles in question are concerned, is as truly 

 destroyed as if the entire mass were converted into ice. 



"The inquiry as to the non-conducting power of fluids an inquiry to 

 which my experiments and observations have given rise is, no doubt, 

 of great interest to science ; and, whatever may be the final result of 

 its investigation, I shall regard myself fortunate in having drawn the 

 attention of a great number of enlightened philosophers towards an 

 object which was long neglected, and which was so worthy of being 

 studied."] 



9 



