254 Account of a curious Phenomenon 



taken the investigation of the phenomena of the propa- 

 gation of heat in fluids, and that they have made a 

 number of new and ingenious experiments, with a view 

 to the further elucidation of that most interesting sub- 

 ject. If I have hitherto abstained from taking public 

 notice of their observations on the opinion I have 

 advanced on that subject in my different publications, 

 it was not from any want of respect for those gentle- 

 men that I remained silent, but because I still found it 

 to be quite impossible to explain the results of my own 

 experiments on any other principles than those which, 

 on the most mature and dispassionate deliberation I had 

 been induced to adopt ; and because my own experi- 

 ments appeared to me to be quite as conclusive (to say 

 no more of them) as those which were opposed to them ; 

 and, lastly, because I considered the principal point in 

 dispute, relative to the passage of heat in fluids, as being 

 so clearly established by the circumstances attending sev- 

 eral great operations of nature, that this evidence did not 

 appear to me to be in danger of being invalidated by 

 conclusions drawn from partial and imperfect experi- 

 ments, and particularly from such as are allowed on all 

 hands to be extremely delicate. 



In all our attempts to cause heat to descend in liquids, 

 the heat unavoidably communicated to the sides of the 

 containing vessel must occasion great uncertainty with 

 respect to the results of the experiment ; and when that 

 vessel is constructed of ice, the flowing down of the 

 water resulting from the thawing of that ice will cause 

 motions in the liquid, and consequently inaccuracies of 

 still greater moment, as I have found from my own 

 experience ; and when thermometers immersed in a 

 liquid at a small distance below its surface acquire 



