2 74 ^f ^^^ Pj'opagatioji of Heat 



tion of a strong Heat, and afforded a very entertaining 

 sight ; but to a scientific observer they were much more 

 than amusing. They detected Nature, as it were, in the 

 very act, in one of her most hidden operations, and ren- 

 dered motions visible in the midst of an invisible me- 

 dium which never had been seen before, and which most 

 probably had never been suspected. 



Encouraged by this success, and confirmed in my 

 opinions respecting the interesting fact I had undertaken 

 to investigate, I now proceeded with confidence to still 

 more direct and decisive experiments. 



It is an opinion which, I believe, is generally received 

 among philosophers, that water cannot be heated in con- 

 tact with ice : reflecting on the subject, I immediately 

 perceived that either this must be a mistake or all my 

 ideas respecting the manner in which Heat is propagated 

 in that Fluid must be erroneous. I saw that as long as 

 the ice floats at the surface of water which is attempted 

 to be warmed over a fire, (or in any other way,) the ice- 

 cold water which results from the melting of the ice 

 must, according to my own hypothesis, descend, and, 

 spreading over the bottom of the containing vessel, and, 

 before it has time to be much heated, being in its turn 

 forced to give place to the ice-cold water which, as long 

 as any ice remains, continues to descend in an uninter- 

 rupted stream as long as this operation is going on, the 

 mass of the water cannot be much heated ; but on the sup- 

 position that water is not a conductor of Heat, accord- 

 ing to the common acceptation of that term, or that 

 Heat cannot pass in that Fluid except when it is carried 

 by its particles, which, being put in motion by the 

 change it occasions in their specific gravity, transport it 

 from place to place, it does not appear how ice, if, instead 



