AN ACCOUNT 



SOME NEW EXPERIMENTS ON THE TEMPERATURE 

 OF WATER AT ITS MAXIMUM DENSITY. 



IN my seventh Essay on the Propagation of Heat 

 in Fluids, and in a paper published in the Philo- 

 sophical Transactions for the year 1804, in which I have 

 given an account of a curious phenomenon frequently ob- 

 served on the glaciers of Chamouny, I have ascribed the 

 melting of the ice below the surface of the ice-cold water 

 to currents of water slightly warmer, and consequently 

 slightly heavier, which descend from the surface to the 

 bottom of the ice-cold water; but the principal fact on 

 which this supposition is founded having been called 

 in question by various persons, I have endeavoured to 

 establish it by new and decisive experiments. 



If it is true that the temperature of water at its maxi- 

 mum density is considerably higher than the freezing- 

 point of that liquid (as was announced many years ago 

 by M. de Luc), and that the communication of heat in 

 liquids is brought about by a movement of circulation 

 caused by a change of density in the particles of the 

 fluid resulting from a change of temperature, the ex- 

 planation that I have given of the phenomenon of the 

 melting of ice covered with a layer of ice-cold water by 

 heat applied to the surface of the water, would seem 



